Test-UEFISystem.ps1

#region License
###############################################################################################
# Copyright 2025 Frank Lesniak

# Permission is hereby granted, free of charge, to any person obtaining a copy of this software
# and associated documentation files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all copies or
# substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
# BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
# DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
###############################################################################################
#endregion License

# Version: 1.0.20250106.0

function Split-StringOnLiteralString {
    # This function takes two positional arguments
    # The first argument is a string, and the string to be split
    # The second argument is a string or char, and it is that which is to split the string in the first parameter
    #
    # Note: This function always returns an array, even when there is zero or one element in it.
    #
    # Example:
    # $result = Split-StringOnLiteralString "foo" " "
    # # $result.GetType().FullName is System.Object[]
    # # $result.Count is 1
    #
    # Example 2:
    # $result = Split-StringOnLiteralString "What do you think of this function?" " "
    # # $result.Count is 7

    trap {
        Write-Error "An error occurred using the Split-StringOnLiteralString function. This was most likely caused by the arguments supplied not being strings"
    }

    if ($args.Length -ne 2) {
        Write-Error "Split-StringOnLiteralString was called without supplying two arguments. The first argument should be the string to be split, and the second should be the string or character on which to split the string."
    } else {
        if ($null -eq $args[0]) {
            # String to be split was $null; return an empty array. Leading comma ensures that
            # PowerShell cooperates and returns the array as desired (without collapsing it)
            , @()
        } elseif ($null -eq $args[1]) {
            # Splitter was $null; return string to be split within an array (of one element).
            # Leading comma ensures that PowerShell cooperates and returns the array as desired
            # (without collapsing it
            , ($args[0])
        } else {
            if (($args[0]).GetType().Name -ne "String") {
                Write-Warning "The first argument supplied to Split-StringOnLiteralString was not a string. It will be attempted to be converted to a string. To avoid this warning, cast arguments to a string before calling Split-StringOnLiteralString."
                $strToSplit = [string]$args[0]
            } else {
                $strToSplit = $args[0]
            }

            if ((($args[1]).GetType().Name -ne "String") -and (($args[1]).GetType().Name -ne "Char")) {
                Write-Warning "The second argument supplied to Split-StringOnLiteralString was not a string. It will be attempted to be converted to a string. To avoid this warning, cast arguments to a string before calling Split-StringOnLiteralString."
                $strSplitter = [string]$args[1]
            } elseif (($args[1]).GetType().Name -eq "Char") {
                $strSplitter = [string]$args[1]
            } else {
                $strSplitter = $args[1]
            }

            $strSplitterInRegEx = [regex]::Escape($strSplitter)

            # With the leading comma, force encapsulation into an array so that an array is
            # returned even when there is one element:
            , [regex]::Split($strToSplit, $strSplitterInRegEx)
        }
    }
}

function Get-PathToDotNetRuntimeEnvironment {
    $strPathToDotNetRuntimeEnvironment = [Runtime.InteropServices.RuntimeEnvironment]::GetRuntimeDirectory()
    # We have the path, but it has a trailing backslash. Let's remove it
    $guid = [guid]::NewGuid()
    $strGUID = $guid.Guid
    $strWorkingPath = Join-Path $strPathToDotNetRuntimeEnvironment $strGUID
    $arrPath = Split-StringOnLiteralString $strWorkingPath $strGUID
    $strPathWithSeparatorButWithoutGUID = $arrPath[0]
    $strScrubbedPath = $strPathWithSeparatorButWithoutGUID.Substring(0, $strPathWithSeparatorButWithoutGUID.Length - 1)
    $strScrubbedPath
}

function Build-CSharpInMemory {
    Param (
        [string]$strCSharpCodeToCompile,
        [array]$arrAdditionalReferences
    )

    $CSharpCodeProvider = New-Object Microsoft.CSharp.CSharpCodeProvider

    $ArrayListReferences = New-Object Collections.ArrayList
    $ArrayListReferences.AddRange( `
        @( `
            (Join-Path (Get-PathToDotNetRuntimeEnvironment) "System.dll"),
            [PSObject].Assembly.Location
        )
    )
    if ($arrAdditionalReferences -ne $null)	{
        if ($arrAdditionalReferences.Count -ge 1) {
            $ArrayListReferences.AddRange($arrAdditionalReferences)
        }
    }

    $CompilerParameters = New-Object System.CodeDom.Compiler.CompilerParameters
    $CompilerParameters.GenerateInMemory = $true
    $CompilerParameters.GenerateExecutable = $false
    $CompilerParameters.OutputAssembly = "custom"
    $CompilerParameters.ReferencedAssemblies.AddRange($ArrayListReferences)
    $CompilerResults = $CSharpCodeProvider.CompileAssemblyFromSource($CompilerParameters, $strCSharpCodeToCompile)

    if ($CompilerResults.Errors.Count) {
        $arrCSharpCodeLines = $strCSharpCodeToCompile.Split("`n")
        foreach ($CompilerError in $CompilerResults.Errors) {
            Write-Host "Error: $($arrCSharpCodeLines[$($CompilerError.Line - 1)])"
            $CompilerError | Out-Default
        }
        Throw "INVALID DATA: Errors encountered while compiling code"
    }
}

function Get-PSVersion {
    # .SYNOPSIS
    # Returns the version of PowerShell that is running.
    #
    # .DESCRIPTION
    # The function outputs a [version] object representing the version of
    # PowerShell that is running.
    #
    # On versions of PowerShell greater than or equal to version 2.0, this
    # function returns the equivalent of $PSVersionTable.PSVersion
    #
    # PowerShell 1.0 does not have a $PSVersionTable variable, so this
    # function returns [version]('1.0') on PowerShell 1.0.
    #
    # .EXAMPLE
    # $versionPS = Get-PSVersion
    # # $versionPS now contains the version of PowerShell that is running.
    # # On versions of PowerShell greater than or equal to version 2.0,
    # # this function returns the equivalent of $PSVersionTable.PSVersion.
    #
    # .INPUTS
    # None. You can't pipe objects to Get-PSVersion.
    #
    # .OUTPUTS
    # System.Version. Get-PSVersion returns a [version] value indiciating
    # the version of PowerShell that is running.
    #
    # .NOTES
    # Version: 1.0.20250106.0

    #region License ####################################################
    # Copyright (c) 2025 Frank Lesniak
    #
    # Permission is hereby granted, free of charge, to any person obtaining
    # a copy of this software and associated documentation files (the
    # "Software"), to deal in the Software without restriction, including
    # without limitation the rights to use, copy, modify, merge, publish,
    # distribute, sublicense, and/or sell copies of the Software, and to
    # permit persons to whom the Software is furnished to do so, subject to
    # the following conditions:
    #
    # The above copyright notice and this permission notice shall be
    # included in all copies or substantial portions of the Software.
    #
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
    # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
    # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
    # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    # SOFTWARE.
    #endregion License ####################################################

    if (Test-Path variable:\PSVersionTable) {
        return ($PSVersionTable.PSVersion)
    } else {
        return ([version]('1.0'))
    }
}

function Test-Windows {
    # .SYNOPSIS
    # Returns $true if PowerShell is running on Windows; otherwise, returns
    # $false.
    #
    # .DESCRIPTION
    # Returns a boolean ($true or $false) indicating whether the current
    # PowerShell session is running on Windows. This function is useful for
    # writing scripts that need to behave differently on Windows and non-
    # Windows platforms (Linux, macOS, etc.). Additionally, this function is
    # useful because it works on Windows PowerShell 1.0 through 5.1, which do
    # not have the $IsWindows global variable.
    #
    # .PARAMETER PSVersion
    # This parameter is optional; if supplied, it must be the version number of
    # the running version of PowerShell. If the version of PowerShell is
    # already known, it can be passed in to this function to avoid the overhead
    # of unnecessarily determining the version of PowerShell. If this parameter
    # is not supplied, the function will determine the version of PowerShell
    # that is running as part of its processing.
    #
    # .EXAMPLE
    # $boolIsWindows = Test-Windows
    #
    # .EXAMPLE
    # # The version of PowerShell is known to be 2.0 or above:
    # $boolIsWindows = Test-Windows -PSVersion $PSVersionTable.PSVersion
    #
    # .INPUTS
    # None. You can't pipe objects to Test-Windows.
    #
    # .OUTPUTS
    # System.Boolean. Test-Windows returns a boolean value indiciating whether
    # PowerShell is running on Windows. $true means that PowerShell is running
    # on Windows; $false means that PowerShell is not running on Windows.
    #
    # .NOTES
    # This function also supports the use of a positional parameter instead of
    # a named parameter. If a positional parameter is used intead of a named
    # parameter, then one positional parameters is required: it must be the
    # version number of the running version of PowerShell. If the version of
    # PowerShell is already known, it can be passed in to this function to
    # avoid the overhead of unnecessarily determining the version of
    # PowerShell. If this parameter is not supplied, the function will
    # determine the version of PowerShell that is running as part of its
    # processing.
    #
    # Version: 1.1.20250106.0

    #region License ########################################################
    # Copyright (c) 2025 Frank Lesniak
    #
    # Permission is hereby granted, free of charge, to any person obtaining a
    # copy of this software and associated documentation files (the
    # "Software"), to deal in the Software without restriction, including
    # without limitation the rights to use, copy, modify, merge, publish,
    # distribute, sublicense, and/or sell copies of the Software, and to permit
    # persons to whom the Software is furnished to do so, subject to the
    # following conditions:
    #
    # The above copyright notice and this permission notice shall be included
    # in all copies or substantial portions of the Software.
    #
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
    # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
    # NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
    # DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
    # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
    # USE OR OTHER DEALINGS IN THE SOFTWARE.
    #endregion License ########################################################

    param (
        [version]$PSVersion = ([version]'0.0')
    )

    function Get-PSVersion {
        # .SYNOPSIS
        # Returns the version of PowerShell that is running.
        #
        # .DESCRIPTION
        # The function outputs a [version] object representing the version of
        # PowerShell that is running.
        #
        # On versions of PowerShell greater than or equal to version 2.0, this
        # function returns the equivalent of $PSVersionTable.PSVersion
        #
        # PowerShell 1.0 does not have a $PSVersionTable variable, so this
        # function returns [version]('1.0') on PowerShell 1.0.
        #
        # .EXAMPLE
        # $versionPS = Get-PSVersion
        # # $versionPS now contains the version of PowerShell that is running.
        # # On versions of PowerShell greater than or equal to version 2.0,
        # # this function returns the equivalent of $PSVersionTable.PSVersion.
        #
        # .INPUTS
        # None. You can't pipe objects to Get-PSVersion.
        #
        # .OUTPUTS
        # System.Version. Get-PSVersion returns a [version] value indiciating
        # the version of PowerShell that is running.
        #
        # .NOTES
        # Version: 1.0.20250106.0

        #region License ####################################################
        # Copyright (c) 2025 Frank Lesniak
        #
        # Permission is hereby granted, free of charge, to any person obtaining
        # a copy of this software and associated documentation files (the
        # "Software"), to deal in the Software without restriction, including
        # without limitation the rights to use, copy, modify, merge, publish,
        # distribute, sublicense, and/or sell copies of the Software, and to
        # permit persons to whom the Software is furnished to do so, subject to
        # the following conditions:
        #
        # The above copyright notice and this permission notice shall be
        # included in all copies or substantial portions of the Software.
        #
        # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
        # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
        # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
        # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
        # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
        # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
        # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
        # SOFTWARE.
        #endregion License ####################################################

        if (Test-Path variable:\PSVersionTable) {
            return ($PSVersionTable.PSVersion)
        } else {
            return ([version]('1.0'))
        }
    }

    if ($PSVersion -ne ([version]'0.0')) {
        if ($PSVersion.Major -ge 6) {
            return $IsWindows
        } else {
            return $true
        }
    } else {
        $versionPS = Get-PSVersion
        if ($versionPS.Major -ge 6) {
            return $IsWindows
        } else {
            return $true
        }
    }
}

function Get-WindowsOSVersion {
    # TODO: Add optional parameter to allow the version of PowerShell to be specified
    #       as a parameter to this function, which can improve performance by avoiding
    #       the overhead of determining the version of PowerShell if it is already
    #       known.
    # TODO: Add optional parameter to skip the check to determine if the current
    #       PowerShell session is running on Windows. This can be useful if the
    #       caller already knows that the current PowerShell session is running on
    #       Windows and wants to avoid the overhead of checking again.

    $strThisScriptVersionNumber = [version]'1.0.20250106.0'

    function Get-PSVersion {
        # .SYNOPSIS
        # Returns the version of PowerShell that is running.
        #
        # .DESCRIPTION
        # The function outputs a [version] object representing the version of
        # PowerShell that is running.
        #
        # On versions of PowerShell greater than or equal to version 2.0, this
        # function returns the equivalent of $PSVersionTable.PSVersion
        #
        # PowerShell 1.0 does not have a $PSVersionTable variable, so this
        # function returns [version]('1.0') on PowerShell 1.0.
        #
        # .EXAMPLE
        # $versionPS = Get-PSVersion
        # # $versionPS now contains the version of PowerShell that is running.
        # # On versions of PowerShell greater than or equal to version 2.0,
        # # this function returns the equivalent of $PSVersionTable.PSVersion.
        #
        # .INPUTS
        # None. You can't pipe objects to Get-PSVersion.
        #
        # .OUTPUTS
        # System.Version. Get-PSVersion returns a [version] value indiciating
        # the version of PowerShell that is running.
        #
        # .NOTES
        # Version: 1.0.20250106.0

        #region License ####################################################
        # Copyright (c) 2025 Frank Lesniak
        #
        # Permission is hereby granted, free of charge, to any person obtaining
        # a copy of this software and associated documentation files (the
        # "Software"), to deal in the Software without restriction, including
        # without limitation the rights to use, copy, modify, merge, publish,
        # distribute, sublicense, and/or sell copies of the Software, and to
        # permit persons to whom the Software is furnished to do so, subject to
        # the following conditions:
        #
        # The above copyright notice and this permission notice shall be
        # included in all copies or substantial portions of the Software.
        #
        # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
        # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
        # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
        # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
        # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
        # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
        # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
        # SOFTWARE.
        #endregion License ####################################################

        if (Test-Path variable:\PSVersionTable) {
            return ($PSVersionTable.PSVersion)
        } else {
            return ([version]('1.0'))
        }
    }

    function Test-Windows {
        # .SYNOPSIS
        # Returns $true if PowerShell is running on Windows; otherwise, returns
        # $false.
        #
        # .DESCRIPTION
        # Returns a boolean ($true or $false) indicating whether the current
        # PowerShell session is running on Windows. This function is useful for
        # writing scripts that need to behave differently on Windows and non-
        # Windows platforms (Linux, macOS, etc.). Additionally, this function is
        # useful because it works on Windows PowerShell 1.0 through 5.1, which do
        # not have the $IsWindows global variable.
        #
        # .PARAMETER PSVersion
        # This parameter is optional; if supplied, it must be the version number of
        # the running version of PowerShell. If the version of PowerShell is
        # already known, it can be passed in to this function to avoid the overhead
        # of unnecessarily determining the version of PowerShell. If this parameter
        # is not supplied, the function will determine the version of PowerShell
        # that is running as part of its processing.
        #
        # .EXAMPLE
        # $boolIsWindows = Test-Windows
        #
        # .EXAMPLE
        # # The version of PowerShell is known to be 2.0 or above:
        # $boolIsWindows = Test-Windows -PSVersion $PSVersionTable.PSVersion
        #
        # .INPUTS
        # None. You can't pipe objects to Test-Windows.
        #
        # .OUTPUTS
        # System.Boolean. Test-Windows returns a boolean value indiciating whether
        # PowerShell is running on Windows. $true means that PowerShell is running
        # on Windows; $false means that PowerShell is not running on Windows.
        #
        # .NOTES
        # This function also supports the use of a positional parameter instead of
        # a named parameter. If a positional parameter is used intead of a named
        # parameter, then one positional parameters is required: it must be the
        # version number of the running version of PowerShell. If the version of
        # PowerShell is already known, it can be passed in to this function to
        # avoid the overhead of unnecessarily determining the version of
        # PowerShell. If this parameter is not supplied, the function will
        # determine the version of PowerShell that is running as part of its
        # processing.
        #
        # Version: 1.1.20250106.0

        #region License ########################################################
        # Copyright (c) 2025 Frank Lesniak
        #
        # Permission is hereby granted, free of charge, to any person obtaining a
        # copy of this software and associated documentation files (the
        # "Software"), to deal in the Software without restriction, including
        # without limitation the rights to use, copy, modify, merge, publish,
        # distribute, sublicense, and/or sell copies of the Software, and to permit
        # persons to whom the Software is furnished to do so, subject to the
        # following conditions:
        #
        # The above copyright notice and this permission notice shall be included
        # in all copies or substantial portions of the Software.
        #
        # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
        # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
        # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
        # NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
        # DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
        # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
        # USE OR OTHER DEALINGS IN THE SOFTWARE.
        #endregion License ########################################################

        param (
            [version]$PSVersion = ([version]'0.0')
        )

        function Get-PSVersion {
            # .SYNOPSIS
            # Returns the version of PowerShell that is running.
            #
            # .DESCRIPTION
            # The function outputs a [version] object representing the version of
            # PowerShell that is running.
            #
            # On versions of PowerShell greater than or equal to version 2.0, this
            # function returns the equivalent of $PSVersionTable.PSVersion
            #
            # PowerShell 1.0 does not have a $PSVersionTable variable, so this
            # function returns [version]('1.0') on PowerShell 1.0.
            #
            # .EXAMPLE
            # $versionPS = Get-PSVersion
            # # $versionPS now contains the version of PowerShell that is running.
            # # On versions of PowerShell greater than or equal to version 2.0,
            # # this function returns the equivalent of $PSVersionTable.PSVersion.
            #
            # .INPUTS
            # None. You can't pipe objects to Get-PSVersion.
            #
            # .OUTPUTS
            # System.Version. Get-PSVersion returns a [version] value indiciating
            # the version of PowerShell that is running.
            #
            # .NOTES
            # Version: 1.0.20250106.0

            #region License ####################################################
            # Copyright (c) 2025 Frank Lesniak
            #
            # Permission is hereby granted, free of charge, to any person obtaining
            # a copy of this software and associated documentation files (the
            # "Software"), to deal in the Software without restriction, including
            # without limitation the rights to use, copy, modify, merge, publish,
            # distribute, sublicense, and/or sell copies of the Software, and to
            # permit persons to whom the Software is furnished to do so, subject to
            # the following conditions:
            #
            # The above copyright notice and this permission notice shall be
            # included in all copies or substantial portions of the Software.
            #
            # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
            # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
            # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
            # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
            # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
            # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
            # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
            # SOFTWARE.
            #endregion License ####################################################

            if (Test-Path variable:\PSVersionTable) {
                return ($PSVersionTable.PSVersion)
            } else {
                return ([version]('1.0'))
            }
        }

        if ($PSVersion -ne ([version]'0.0')) {
            if ($PSVersion.Major -ge 6) {
                return $IsWindows
            } else {
                return $true
            }
        } else {
            $versionPS = Get-PSVersion
            if ($versionPS.Major -ge 6) {
                return $IsWindows
            } else {
                return $true
            }
        }
    }

    $versionPS = Get-PSVersion
    $boolWindows = Test-Windows -PSVersion $versionPS
    if ($boolWindows) {
        if ($versionPS.Major -ge 3) {
            $arrCIMInstanceOS = @(Get-CimInstance -Query "Select Version from Win32_OperatingSystem" -ErrorAction Ignore)
            if ($arrCIMInstanceOS.Count -eq 0) {
                Write-Error "No instances of Win32_OperatingSystem found!"
                $null
            }
            if ($arrCIMInstanceOS.Count -gt 1) {
                Write-Warning "More than one instance of Win32_OperatingSystem returned. Will only use first instance."
            }
            if ($arrCIMInstanceOS.Count -ge 1) {
                [System.Version](($arrCIMInstanceOS[0]).Version)
            }
        } else {
            $arrManagementObjectOS = @(Get-WmiObject -Query "Select Version from Win32_OperatingSystem" -ErrorAction SilentlyContinue)
            if ($arrManagementObjectOS.Count -eq 0) {
                Write-Error "No instances of Win32_OperatingSystem found!"
                $null
            }
            if ($arrManagementObjectOS.Count -gt 1) {
                Write-Warning "More than one instance of Win32_OperatingSystem returned. Will only use first instance."
            }
            if ($arrManagementObjectOS.Count -ge 1) {
                [System.Version](($arrManagementObjectOS[0]).Version)
            }
        }
    } else {
        $null
    }
}

function Get-PathToWindowsFolder {
    # TODO: Add optional parameter to allow the version of PowerShell to be specified
    #       as a parameter to this function, which can improve performance by avoiding
    #       the overhead of determining the version of PowerShell if it is already
    #       known.
    # TODO: Add optional parameter to skip the check to determine if the current
    #       PowerShell session is running on Windows. This can be useful if the
    #       caller already knows that the current PowerShell session is running on
    #       Windows and wants to avoid the overhead of checking again.

    # Version: 1.0.20250106.0

    function Test-Windows {
        # .SYNOPSIS
        # Returns $true if PowerShell is running on Windows; otherwise, returns
        # $false.
        #
        # .DESCRIPTION
        # Returns a boolean ($true or $false) indicating whether the current
        # PowerShell session is running on Windows. This function is useful for
        # writing scripts that need to behave differently on Windows and non-
        # Windows platforms (Linux, macOS, etc.). Additionally, this function is
        # useful because it works on Windows PowerShell 1.0 through 5.1, which do
        # not have the $IsWindows global variable.
        #
        # .PARAMETER PSVersion
        # This parameter is optional; if supplied, it must be the version number of
        # the running version of PowerShell. If the version of PowerShell is
        # already known, it can be passed in to this function to avoid the overhead
        # of unnecessarily determining the version of PowerShell. If this parameter
        # is not supplied, the function will determine the version of PowerShell
        # that is running as part of its processing.
        #
        # .EXAMPLE
        # $boolIsWindows = Test-Windows
        #
        # .EXAMPLE
        # # The version of PowerShell is known to be 2.0 or above:
        # $boolIsWindows = Test-Windows -PSVersion $PSVersionTable.PSVersion
        #
        # .INPUTS
        # None. You can't pipe objects to Test-Windows.
        #
        # .OUTPUTS
        # System.Boolean. Test-Windows returns a boolean value indiciating whether
        # PowerShell is running on Windows. $true means that PowerShell is running
        # on Windows; $false means that PowerShell is not running on Windows.
        #
        # .NOTES
        # This function also supports the use of a positional parameter instead of
        # a named parameter. If a positional parameter is used intead of a named
        # parameter, then one positional parameters is required: it must be the
        # version number of the running version of PowerShell. If the version of
        # PowerShell is already known, it can be passed in to this function to
        # avoid the overhead of unnecessarily determining the version of
        # PowerShell. If this parameter is not supplied, the function will
        # determine the version of PowerShell that is running as part of its
        # processing.
        #
        # Version: 1.1.20250106.0

        #region License ########################################################
        # Copyright (c) 2025 Frank Lesniak
        #
        # Permission is hereby granted, free of charge, to any person obtaining a
        # copy of this software and associated documentation files (the
        # "Software"), to deal in the Software without restriction, including
        # without limitation the rights to use, copy, modify, merge, publish,
        # distribute, sublicense, and/or sell copies of the Software, and to permit
        # persons to whom the Software is furnished to do so, subject to the
        # following conditions:
        #
        # The above copyright notice and this permission notice shall be included
        # in all copies or substantial portions of the Software.
        #
        # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
        # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
        # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
        # NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
        # DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
        # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
        # USE OR OTHER DEALINGS IN THE SOFTWARE.
        #endregion License ########################################################

        param (
            [version]$PSVersion = ([version]'0.0')
        )

        function Get-PSVersion {
            # .SYNOPSIS
            # Returns the version of PowerShell that is running.
            #
            # .DESCRIPTION
            # The function outputs a [version] object representing the version of
            # PowerShell that is running.
            #
            # On versions of PowerShell greater than or equal to version 2.0, this
            # function returns the equivalent of $PSVersionTable.PSVersion
            #
            # PowerShell 1.0 does not have a $PSVersionTable variable, so this
            # function returns [version]('1.0') on PowerShell 1.0.
            #
            # .EXAMPLE
            # $versionPS = Get-PSVersion
            # # $versionPS now contains the version of PowerShell that is running.
            # # On versions of PowerShell greater than or equal to version 2.0,
            # # this function returns the equivalent of $PSVersionTable.PSVersion.
            #
            # .INPUTS
            # None. You can't pipe objects to Get-PSVersion.
            #
            # .OUTPUTS
            # System.Version. Get-PSVersion returns a [version] value indiciating
            # the version of PowerShell that is running.
            #
            # .NOTES
            # Version: 1.0.20250106.0

            #region License ####################################################
            # Copyright (c) 2025 Frank Lesniak
            #
            # Permission is hereby granted, free of charge, to any person obtaining
            # a copy of this software and associated documentation files (the
            # "Software"), to deal in the Software without restriction, including
            # without limitation the rights to use, copy, modify, merge, publish,
            # distribute, sublicense, and/or sell copies of the Software, and to
            # permit persons to whom the Software is furnished to do so, subject to
            # the following conditions:
            #
            # The above copyright notice and this permission notice shall be
            # included in all copies or substantial portions of the Software.
            #
            # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
            # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
            # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
            # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
            # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
            # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
            # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
            # SOFTWARE.
            #endregion License ####################################################

            if (Test-Path variable:\PSVersionTable) {
                return ($PSVersionTable.PSVersion)
            } else {
                return ([version]('1.0'))
            }
        }

        if ($PSVersion -ne ([version]'0.0')) {
            if ($PSVersion.Major -ge 6) {
                return $IsWindows
            } else {
                return $true
            }
        } else {
            $versionPS = Get-PSVersion
            if ($versionPS.Major -ge 6) {
                return $IsWindows
            } else {
                return $true
            }
        }
    }

    $boolWindows = Test-Windows
    if ($boolWindows) {
        $env:windir
    } else {
        $null
    }
}

function Get-PathToWindowsSetupLog {
    $strWindowsPath = Get-PathToWindowsFolder
    if ($null -ne $strWindowsPath) {
        $strWorkingPath = Join-Path $strWindowsPath "Panther"
        $strWorkingPath = Join-Path $strWorkingPath "setupact.log"
        $strWorkingPath
    } else {
        $null
    }
}

function Get-DetectedBootEnvironmentFromWindowsSetupLog {
    # Returns a string containing the "detected boot environment" from the Windows Setup log.
    # If the log could not be read, or if this function is run on non-Windows, the function
    # returns $null
    #
    #region OriginalLicense
    # Although substantial modifications have been made, the original portions of
    # Get-LogFileFirmwareType that are incorporated into
    # Get-DetectedBootEnvironmentFromWindowsSetupLog are subject to the following license:
    ###########################################################################################
    # Copyright (c) 2015 Chris Warwick
    #
    # Permission is hereby granted, free of charge, to any person obtaining a copy of this
    # software and associated documentation files (the "Software"), to deal in the Software
    # without restriction, including without limitation the rights to use, copy, modify, merge,
    # publish, distribute, sublicense, and/or sell copies of the Software, and to permit
    # persons to whom the Software is furnished to do so, subject to the following conditions:
    #
    # The above copyright notice and this permission notice shall be included in all copies or
    # substantial portions of the Software.
    #
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
    # INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
    # PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
    # FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
    # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    # DEALINGS IN THE SOFTWARE.
    ###########################################################################################
    #endregion OriginalLicense

    $versionPS = Get-PSVersion
    $strPathToWindowsSetupLog = Get-PathToWindowsSetupLog
    if ($null -ne $strPathToWindowsSetupLog) {
        if ($versionPS.Major -ge 3) {
            $arrMatchInfo = @(Select-String 'Detected boot environment' $strPathToWindowsSetupLog -AllMatches -ErrorAction Ignore)
        } else {
            $arrMatchInfo = @(Select-String 'Detected boot environment' $strPathToWindowsSetupLog -AllMatches -ErrorAction SilentlyContinue)
        }
        if ($arrMatchInfo.Count -ge 1) {
            $arrStrBootEnvironments = @($arrMatchInfo | ForEach-Object {
                    ($_.Line) -replace ".*:\s+"
                })

            if ($arrStrBootEnvironments.Count -gt 1) {
                Write-Warning ("More than one detected boot environment found in Windows Setup Log (" + $strPathToWindowsSetupLog + "). Returning only first one.")
            }

            $arrStrBootEnvironments[0]
        } else {
            Write-Warning ("Read access to file " + $strPathToWindowsSetupLog + " was denied; try running PowerShell as an administrator (elevated)")
            $null
        }
    } else {
        $null
    }
}

function Test-FirmwareEnvironmentVariableAWin32API {
    # Returns $true if the GetFirmwareEnvironmentVariableA Win32 API is able to be called,
    # which indicates that the system is UEFI. Returns $false otherwise.
    #
    # NOTE: Returns $null if run on non-Windows system
    #
    #region OriginalLicense
    # Although substantial modifications have been made, the original portions of
    # Get-FirmwareEnvironmentVariableAPI that are incorporated into
    # Test-FirmwareEnvironmentVariableAWin32API are subject to the following license:
    ###########################################################################################
    # Copyright (c) 2015 Chris Warwick
    #
    # Permission is hereby granted, free of charge, to any person obtaining a copy of this
    # software and associated documentation files (the "Software"), to deal in the Software
    # without restriction, including without limitation the rights to use, copy, modify, merge,
    # publish, distribute, sublicense, and/or sell copies of the Software, and to permit
    # persons to whom the Software is furnished to do so, subject to the following conditions:
    #
    # The above copyright notice and this permission notice shall be included in all copies or
    # substantial portions of the Software.
    #
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
    # INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
    # PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
    # FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
    # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    # DEALINGS IN THE SOFTWARE.
    ###########################################################################################
    #endregion OriginalLicense

    # Use the GetFirmwareEnvironmentVariable Win32 API.
    # From MSDN
    # (http://msdn.microsoft.com/en-ca/library/windows/desktop/ms724325%28v=vs.85%29.aspx):
    # "Firmware variables are not supported on a legacy BIOS-based system. The
    # GetFirmwareEnvironmentVariable function will always fail on a legacy BIOS-based system,
    # or if Windows was installed using legacy BIOS on a system that supports both legacy BIOS
    # and UEFI."
    # "To identify these conditions, call the function with a dummy firmware environment name
    # such as an empty string ("") for the lpName parameter and a dummy GUID such as
    # "{00000000-0000-0000-0000-000000000000}" for the lpGuid parameter. On a legacy BIOS-based
    # system, or on a system that supports both legacy BIOS and UEFI where Windows was
    # installed using legacy BIOS, the function will fail with ERROR_INVALID_FUNCTION. On a
    # UEFI-based system, the function will fail with an error specific to the firmware, such as
    # ERROR_NOACCESS, to indicate that the dummy GUID namespace does not exist."
    #
    # From PowerShell, we can call the API via P/Invoke from a compiled C# class using
    # Add-Type.  In Win32 any resulting API error is retrieved using GetLastError(), however,
    # this is not reliable in .Net (see
    # blogs.msdn.com/b/adam_nathan/archive/2003/04/25/56643.aspx), instead we mark the pInvoke
    # signature for GetFirmwareEnvironmentVariableA with SetLastError=true and use
    # Marshal.GetLastWin32Error()
    #
    # Note: The GetFirmwareEnvironmentVariable API requires the SE_SYSTEM_ENVIRONMENT_NAME
    # privilege.  In the Security Policy editor this equates to "User Rights Assignment":
    # "Modify firmware environment values" and is granted to Administrators by default. Because
    # we don't actually read any variables this permission appears to be optional.

    $versionPS = Get-PSVersion
    $boolWindows = Test-Windows -PSVersion $versionPS

    if ($boolWindows) {
        $versionWindows = Get-WindowsOSVersion
        if ($versionWindows -ge ([System.Version]"6.1")) {
            $strCSharpCode = @"
using System;
using System.Runtime.InteropServices;
namespace FrankLesniak
{
    public class CheckUEFI
    {
        [DllImport("kernel32.dll", SetLastError=true)]
        static extern UInt32 
        GetFirmwareEnvironmentVariableA(string lpName, string lpGuid, IntPtr pBuffer, UInt32 nSize);
        const int ERROR_INVALID_FUNCTION = 1; 
        public static bool IsUEFI()
        {
            // Try to call the GetFirmwareEnvironmentVariable API.  This is invalid on legacy BIOS.
            GetFirmwareEnvironmentVariableA("","{00000000-0000-0000-0000-000000000000}",IntPtr.Zero,0);
            if (Marshal.GetLastWin32Error() == ERROR_INVALID_FUNCTION)
                return false;     // API not supported (INVALID_FUNCTION); this is a legacy BIOS
            else
                return true;      // Call to API is supported.  This is UEFI.
        }
    }
}
"@
            if ($versionPS.Major -ge 2) {
                Add-Type -Language CSharp -TypeDefinition $strCSharpCode
            } else {
                Build-CSharpInMemory $strCSharpCode
            }

            [FrankLesniak.CheckUEFI]::IsUEFI()
        } else {
            # Is Windows, but is a version that does not support
            # GetFirmwareEnvironmentVariableA API
            $null
        }
    } else {
        # Not Windows
        $null
    }
}

function Get-FirmwareTypeFromGetFirmwareTypeWin32API {
    # Returns an integer that indicates the firmware type on the system.
    # Returns:
    #   0 if the type is unknown
    #   1 if the type is BIOS
    #   2 if the type is UEFI
    #   3 if the type is "Max"
    #
    # NOTE: Returns $null if run on non-Windows system
    #
    #region OriginalLicense
    # Although substantial modifications have been made, the original portions of
    # Get-FirmwareTypeAPI that are incorporated into
    # Get-FirmwareTypeFromGetFirmwareTypeWin32API are subject to the following license:
    ###########################################################################################
    # Copyright (c) 2015 Chris Warwick
    #
    # Permission is hereby granted, free of charge, to any person obtaining a copy of this
    # software and associated documentation files (the "Software"), to deal in the Software
    # without restriction, including without limitation the rights to use, copy, modify, merge,
    # publish, distribute, sublicense, and/or sell copies of the Software, and to permit
    # persons to whom the Software is furnished to do so, subject to the following conditions:
    #
    # The above copyright notice and this permission notice shall be included in all copies or
    # substantial portions of the Software.
    #
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
    # INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
    # PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
    # FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
    # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    # DEALINGS IN THE SOFTWARE.
    ###########################################################################################
    #endregion OriginalLicense
    #
    # In Windows 8/Server 2012 and above there's an API that directly returns the firmware type
    # and doesn't rely on a hack. GetFirmwareType() in kernel32.dll
    # (http://msdn.microsoft.com/en-us/windows/desktop/hh848321%28v=vs.85%29.aspx) returns a
    # pointer to a FirmwareType enum that defines the following:
    #
    # typedef enum _FIRMWARE_TYPE {
    #   FirmwareTypeUnknown = 0,
    #   FirmwareTypeBios = 1,
    #   FirmwareTypeUefi = 2,
    #   FirmwareTypeMax = 3
    # } FIRMWARE_TYPE, *PFIRMWARE_TYPE;
    # This API call can be called in .Net via P/Invoke.

    $versionPS = Get-PSVersion
    $boolWindows = Test-Windows -PSVersion $versionPS

    if ($boolWindows) {
        $versionWindows = Get-WindowsOSVersion
        if ($versionWindows -ge ([System.Version]"6.2")) {
            $strCSharpCode = @"
using System;
using System.Runtime.InteropServices;
namespace FrankLesniak
{
    public class FirmwareType
    {
        [DllImport("kernel32.dll")]
        static extern bool GetFirmwareType(ref uint FirmwareType);
        public static uint GetFirmwareType()
        {
            uint firmwaretype = 0;
            if (GetFirmwareType(ref firmwaretype))
                return firmwaretype;
            else
                return 0;   // API call failed, just return 'unknown'
        }
    }
}
"@
            if ($versionPS.Major -ge 2) {
                Add-Type -Language CSharp -TypeDefinition $strCSharpCode
            } else {
                Build-CSharpInMemory $strCSharpCode
            }

            [FrankLesniak.FirmwareType]::GetFirmwareType()
        } else {
            # Is Windows, but is a version that does not support
            # GetFirmwareEnvironmentVariableA API
            $null
        }
    } else {
        # Not Windows
        $null
    }
}

function Test-UEFISystem {
    # Returns $true if the system is UEFI
    # Returns $false if the system is not UEFI (i.e., it is BIOS)
    # Returns $null if the system type could not be determined
    #
    #region OriginalLicense
    # Although substantial modifications have been made, the original portions of
    # Get-FirmwareType that are incorporated into Test-UEFISystem are subject to the following
    # license:
    ###########################################################################################
    # Copyright (c) 2015 Chris Warwick
    #
    # Permission is hereby granted, free of charge, to any person obtaining a copy of this
    # software and associated documentation files (the "Software"), to deal in the Software
    # without restriction, including without limitation the rights to use, copy, modify, merge,
    # publish, distribute, sublicense, and/or sell copies of the Software, and to permit
    # persons to whom the Software is furnished to do so, subject to the following conditions:
    #
    # The above copyright notice and this permission notice shall be included in all copies or
    # substantial portions of the Software.
    #
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
    # INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
    # PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
    # FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
    # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    # DEALINGS IN THE SOFTWARE.
    ###########################################################################################
    #endregion OriginalLicense
    $boolWindows = Test-Windows
    if ($boolWindows) {
        $versionWindowsOS = Get-WindowsOSVersion
        if ($versionWindowsOS -lt ([System.Version]"6.0")) {
            # Windows 5.x running PowerShell - these do not support UEFI
            $false
        } elseif ($versionWindowsOS -ge ([System.Version]"6.2")) {
            # Windows 8 / Windows Server 2012, or newer
            $intFirmwareType = Get-FirmwareTypeFromGetFirmwareTypeWin32API
            if ($null -ne $intFirmwareType) {
                if ($intFirmwareType -eq 2) {
                    $true # UEFI
                } else {
                    $false # Not UEFI, must be BIOS
                }
            } else {
                # Error condition
                $null
            }
        } elseif ($versionWindowsOS -ge ([System.Version]"6.1")) {
            # Windows 7 / Windows Server 2008 R2
            Test-FirmwareEnvironmentVariableAWin32API
        } else {
            $strDetectedBootEnvironment = Get-DetectedBootEnvironmentFromWindowsSetupLog
            switch -Regex ($strDetectedBootEnvironment) {
                "^U?EFI$" {
                    $true
                }
                default {
                    $false
                }
            }
        }
    } else {
        # TO-DO: write code for FreeBSD/Linux
        # return $null for now
        $null
    }
}