Huh. I have installed service packs on Windows NT, 2000 and now 2003 for years and never had any problem doing so. Upgrading the OS from a different OS line (NT -> 2000, 2000 -> XP, etc) might prove shaky, but installing service packs is usually definitely not. Most often, it's not that different from installing a bunch of hotfixes. If you think administrators have nothing else to do than reinstalling from scratch every time a service pack is out, you're obviously either kidding me or ignorant. Pick one. <{POST_SNAPBACK}> Couldn't have said it better myself.