Yes, that's the thing I always forget, the way Windows deals with multiple incompatible versions of msvcrt is that every application ships its own copy of libc, and hopefully the installer is well-written enough to only copy it into place if it's newer than the newest release of the same major version that's already there, lest a random app re-introduces a bunch of security issues that should have been closed by the last security update for every other application that uses the same msvcrt.

...and by "forget", I mean "block out due to trauma, because surely it can't be that stupid".