Generally no, this isn't possible, but Sun Microsystems I believe recently came out with a VM that can do this. I can't guarantee that it will run on Windows, and I can't even think of the name at the moment, but it can't hurt to look into it.
Also, as I understand it, that free Windows 7 beta Microsoft is offering requires you install it over Vista, so it might be a moot question if you're running XP.
I have a Athlon X2 64 PC running XP Pro 32 bit OS.
I want to load a copy of Windows7 (64 bit)in a MS Virtual PC session.
Is it possible to load the 64 bit version of microsoft VPC?
My guess is that the answer is No and infact to be able to use Win7 64 bit I will need to dual boot rather than use virtual PC to get the full functionality of 64 bit processing.
Would it work if I use the VPC 32 bit version