Installing ActivePython screws up PATH in Wine?

[Dan Kegel]

In Wine, I can happily install mingw and add it to the
global PATH by editing the registry key PATH in
[System\\CurrentControlSet\\Control\\Session Manager\\Environment]

However, once I install ActivePython, something
gets screwed up, and from then on, 'PATH' in CMD
says
  PATH="C:\Python26\";;C:\Python26\;
even if I remove that bit from that registry key
and add other directories.
Anyone know what the heck is going on?