I have Windows XP installed via Parallels, but I want to try Boot Camp. Can I install the same copy? or do I need to uninstall the one in Parallels first?
You don't need to uninstall the parallels version but when the bootcamp version needs to be activated it may fail (microsoft keeps the activation on file for 128 days i think). You'll need to call them explain what you're doing - installing it back on the same computer.