I have a socket 478 SL7QB P4, which has x64 support, and a motherboard which supports x64. I will be using the board sometime soonish to test my socket 478 collection, but as well as testing most CPUs using XP, I want to also have XP64 set up, to run folding at home and do other stuff with the SL7QB. Is it straightforward to dual boot two different versions of the same Windows generation, or will I need to swap hard drives (or, more likely, SSDs) to do that?