Yeah, that's a possibility, but in the present time Vista is not a good choice for gamers, especially not retro gamers. If I just think about my beloved emulators, that are not going to work, my heart sinks.
A solution could be partitioning the hard drive and installing XP on a new partition, choosing which one to boot on computer start, but that's not easy for non-computer nerds and I wouldn't know how to do it myself.