OK, so the define is not going to work. For Python extensions built 
through distutils, the msvc9compiler_stripruntimes.diff patch will 
work: it will remove just the dependency on the VC90runtimes. It will 
leave other assembly dependencies if they are there.

For the .pyd's and .dll's in the DLLs folder: I have opened them in a 
hex editor, and just by hand replaced the <assemblyIdentity> entry for 
the VC90runtimes in each file with spaces. I can confirm that this 
works, also for _tkinter, for which tk85.dll has an additional 
dependency on Windows Common Controls (though this one was available in 
my WinSXS). What would be the best way to integrate a search/replace 
operation like this in the Python build process? Is the manifest 
generated as a seperate file here first as well, or is it directly 
embedded?