I need to use Windows XP to run one application. I’d like to do this as cheaply as possible. Amazon has XP products meant for a system builder for under $100. It only allows one activation as far as I can tell. I intend to get the latest version of Parallels Desktop. I intend to put my Windows virtual machine on an external usb drive, which appears to be a valid way of configuring things. I may need to get a new Macbook in the next few months since this one is getting old and a little cranky. I’m assuming I can transfer the Parallels Desktop license to another machine, and that appears to be a question for a different forum. Anyway, lets say I can do that for the purpose of this discussion. Will I have to recreate the Windows virtual machine and reinstall Windows? I really don’t want to have to buy another copy of Windows XP if I upgrade my Mac, nor do I wish to buy a more expensive version of XP that would allow additional activations. Since I’ll be putting the Windows VM on an external drive, will I have to do either of those things? Thanks