try scons.py --clean

SCons likes to remember the fact that a previous step errored, and then refuse to every actually check again.

@wolfy1339 (View Post)
The --win flag is entirely optional and not needed since a year ago.

@jBot-42 (View Post)
Can you post config.log? My guess is that you didn't add C:\MinGW\bin to path, see this section: https://powdertoy.co.uk/Wiki/W/Compiling_for_Windows_with_scons.html#Add_variables_to_Path
Posting config.log to something like http://pastebin.com will help though.

I see a few possible solutions here: http://stackoverflow.com/questions/3848357/createprocess-no-such-file-or-directory

Try rebooting, if that doesn't work then apparently you can add 'C:\MinGW\libexec\gcc\mingw32\MinGW-Version' to the path (but i'm not so sure on this)