OK, I'll only be using Parallels at home, and only want to run a single Windows. I do have more than one Mac though, and if I store the VM hdd on a fileserver, then I was hoping that I'd be able to boot it as a guest OS from different machines. I'm happy to buy multiple copies of Parallel's software to do this (I think the price is a bargain) but wouldn't be keen on buying multiple XPs. And of course, having a different XP on each machine would invalidate my whole idea. So can XP see out of the VM, and detect if it's running on different hardware? Or does the inside of the VM look the same to XP, no matter where it's running? I did some searches for 'activation' but couldn't find an answer to this specific question. Thanks!