Skip, yes Windows 7 has a compatibility mode- IF you have 7 Pro or higher, IF you have a compatible dual or quad core processor (not all enable the threading mode required), PLUS your motherboard's BIOS allows the enabled CPU's mode to make it go. A lot of ducks must be in a row... FWIW, this is the same setup for running virtual machines in your computer, though I'm still wondering why in the world one would want to in a non-server given the license requirements not changing. Running another virtual OS still requires a beefy machine, and the license and installation of that OS and requires more overhead than simply running that other OS more cleanly from another partition or hard drive. From a server- that is another matter entirely.
Stu AF6IT