Developer, xorloser, created an installable PSPDev environment for Win32. According to the good developer, this was done using the latest toolchain script and pspsdk available at that time.
This contains all you need to start developing for psp on a windows machine, presented in a nice, easy to use, installable format.

It contains the latest pspdev compiler and tools built on the GCC v4.0.2 toolchain and patches. It also contains the current (direct from svn) version of pspsdk precompiled. xorloser would just like to remind those who will be getting this that when installing, DO NOT install to a directory path that contains spaces! He also wants to extend his thanks to all those who helped make the toolchain and pspsdk what it is today.

Changelog:
* uname now returns the correct system type (windows) for scripted stuff
* rm.exe now deletes files using wildcards
* rmdir.exe has been copied to cyg-rmdir.exe (to resolve dos rmdir command conflicts)
* mkdir.exe has been copied to cyg-mkdir.exe (to resolve dos mkdir command conflicts)
* echo.exe has been copied to cyg-echo.exe (to resolve dos echo command conflicts)