Better not to go into C:\windows for tools.
It is there (PlatformSDK), but under the bin/win64 dir. (lib.exe also). They work fine for 32-bit windows. My guess is that MS has not written 64-bit versions of these tools yet and just lets the 32-bit versions run in emulation mode on 64-bit machines...
2nd, I don't like the idea of the default compiler changing on me when importing projects. If I was working with a lot of msw, prj files then I'm most likely to use vc++ toolkit by default.
You should probably just remove the -Wall flag. This has to be fixed. CodeBlocks should be better at emitting correct flags for the selected compiler, e.g. get rid of these on creating new project (with vc++ toolkit as default):
-pipe
-mthreads
-fno-pcc-struct-return
-fno-rtti
-fno-exceptions