I think you may have gone a different route already (PCMover) but wanted to answer your questions. Win 7 Pro, Ultimate and Enterprise give you the ability to download a feature called XP Mode which is a virtual machine that runs a fully licensed copy of XP.
There are also tools you can use that will create an image of your XP disk and then use that image as a virtual machine. http://www.techrepublic.com/picture...g-windows-xp-system-into-a-virtual-machine/1/
The problem with both of these solutions is that you end up still running XP so you really haven't upgraded.
I have already installed Win 7 64 Ultimate on a hard drive and installed the virtual machine and XP Pro. My main concern was running Outlook Express. I have the store folder on G drive in folder OE. Running the virtual XP, it won't let me select that folder as my store folder. If I could make a virtual machine out of my existing XP system and run it under Win 7 when needed, that would solve my problem. Eventually I will upgrade my other software to Win 7 64 bit versions.