What games do you play? If your problem is with games that run too fast on a modern PC to play, then I too would be interested to know of an emulator that will turn your PC into a 66Mhz equivalent.
Old DOS games like Duke Nukem 3D and Doom should run perfectly fine in XP running on a modern PC. Actually, I recentally fired up some Duke3d on my 1.2Ghz WinXP box.