sometimes it does work. i recommend removing all the drivers (sound,video,chipset,etc) before you transplant the hdd to it's new home. you might want to do a repair option during xp install (if the installing detects a previous installation of windows. if not then you need to reinstall). good thing about the repair, you don't lose programs, documents, games. it will only replace your windows files with the original files that came in you cd. bad thing, you lose all windows updates. then you install the drivers. ^_^