Attached Link: MS Virtual PC Download.

I failed to mention that Vista Ultimate contains a program called MS Virtual PC, or you can obtain the program free for x86 and or x64.  

Caution:  it only installs on specific programs, not all can run the program, however, with a system that can run Virtual PC, MS says you can run any MS OS as a virtual machine.  

You do have to have a extra drive letter, but you do not have to duel boot with a virtual drive.  The only drawback is that XP would run inside of Vista and use existing resources.  So you would want to have a big video card and lots of memory. 

 

jankeen.com