No problem, x64 Windows can run most x86 programs without problems.

In fact, there is no option here, since there is NO x64 build of Visual Studio, so the 32 bits version is really the only choice. It can still compile and debug both 32 and 64 bits programs, you lose no functionality. See more about it here: Visual Studio: Why is there no 64 bit version? (yet) - Rico Mariani's Performance Tidbits - Site Home - MSDN Blogs