Correct PuTTY url

windows-environment.md

@@ -12,7 +12,7 @@ One of the pain points we hear from users is that the command line console in Wi
 * **Cygwin:** [Cygwin](http://cygwin.com/index.html) can be handy if you're more familiar with bash, or are trying to use a Node app that assumes a *nix environment. Cygwin is a distribution of popular GNU and other open source tools running on Microsoft Windows. The core part is the Cygwin library which provides the POSIX system calls and environment these programs expect.
 * **Git for Windows** [Git for windows](https://git-for-windows.github.io/) provides native versions of the BASH shell and some *nix utilites in addition to the command line git and GUI tool. It is probably the best of shells based on MSYS/MinGW but still supplies ports of older versions of the *nix utilities. Works very well in combination with [ConEmu](https://conemu.github.io/).    
 * **GitHub Desktop** [GitHub Desktop](https://desktop.github.com/) (previously GitHub for Windows) is primarilarly a GUI but it also includes a version of MSYS/MinGW Bash.  
-* **Putty:** an SSH and telnet client: https://www.putty.org/.
+* **Putty:** an SSH and telnet client: https://www.chiark.greenend.org.uk/~sgtatham/putty/.
 * **WinSCP:** an (S)FTP client that also supports SCP and webDAV: https://winscp.net/.
 * **Fiddler:** a web debugging tool: https://www.telerik.com/fiddler. In general, people use it for the browser-side debugging, but you can also [configure it](http://stackoverflow.com/questions/8697344/can-a-proxy-like-fiddler-be-used-with-node-jss-clientrequest) to view server-side requests from Node.js.