Boot up the VM and go into Device Manager and remove any drivers, so just bog standard windows graphics, sound, motherboard, HDD controller etc.
Look at an imaging tool like Norton Ghost and create an image of the PC.
You can do this on your physical machine through the network.
Then once you have the image you "should" be able to restore it to a physical machine without too many issues?
Sorry to be a grave digger. Now I have a hard drive out of an old computer that was running XP and I've plugged it into my new hard drive dock and was wondering if I was to use VM Ware converter would it be possible to make it into a VM?