It is not 'processor specific' per say. When you compile a program on a P2 processor, it won't only work on other P2's, it will run on all intel PLATFORMS. C++ is PLATFORM SPECIFIC, if compiled on an Ultra Sparc processor, it will run on a great deal of Ultra Sparc processors, not just the one it was compiled on. I'm not sure how this exactly related to hand coding windows API calls, maybe you can be more specific.