[Jack Jansen]
The question I mean is that the GPL says "You shall not link against commercial libraries, unless they are part of the base OS". The second part of that sentence could be considered true for the VC6 version of MSVCRT, but not for the VC7 one. Actually, Microsoft strongly suggest you ship msvcr71.dll (or whatever the name) with the application, and not put it into /System. That appears to me to be a definite no-no for GPL software.
Python isn't released under the GPL, so what specifically are you asking about? Whether an author of a Python 2.4 derivative work targeting Windows can put their work under the GPL? I expect that's more a question of the conditions under which Microsoft licenses msvcr71.dll. They've had some goofy language in the past purporting to prevent redistribution of MS redistributables in packages under "viral" licenses. Maybe they still do. I expect that by "You shall not link ..." (which doesn't appear in the GPL), you have in mind the confusing requirements of GPL Version 2 Section 3. That exempts copiers and distributors from including full source code for "major components ... of the operating system on which the executable runs", *except* "unless that component itself accompanies the executable". Python installers have always included the MS C runtime DLLs, so there was no relief in the GPL for VC6. I suggest asking the FSF directly what they believe. Regardless of internal consistency, I expect they'll develop a rationale for saying "sure, fine". The questions really have nothing to do with Python.