Windows Scripting Host is part of operating system. As default there is VB Script and JScript installed in WSH and you can install any additional language - Python, PHP, ... PSPad soesn't know what language has user installed. It gets list of installed languages from WSH interface.
I don't use Python, so I am sorry, I can't be more helpfull Here are some problems and solutions with Active Python and WSH: https://community.activestate.com/forums/activepython-support-0 -- <http://forum.pspad.com/read.php?2,65617,67595> PSPad freeware editor http://www.pspad.com
