XP Pro here, the install of SP2 was fine. The **problem** was Norton.
I've worked with Norton since about 1990 or so including Macintosh and have had nothing but trouble with it. It worms its way down into your system replacing vital DLL's, including internet DLL's, (on a win system of course) with Norton-specific DLL's. Uninstalls are a nightmare.
After SP2, I had corrupted Norton-specific registry entries . . the manual install on their site wouldn't work right . . . yet right there on their website it says "There are no known issues with Norton products and the install of SP2 . . . " BS . . . . internet was at a crawl . . couldn't even download a text file because it kept kicking off "Your security settings won't allow this type of file to be downloaded."
I have a friend (
http://www.pchell.com) that built me a slipstream XP CD that combines an install of XP with SP2, using my VALID number. I reformatted the HD, reinstalled without Norton, and all is well again.
There are those that will say "bah, I never had problem with Norton, it's great" and it is - as long as you don't hit a snag. When you do - I pity you.
You don't have to pay highly for anti-virus software and daily updates. FREE for personal use, works on all platforms EXCEPT win2k, is
Grisoft's AVG. My sys admins have been using this for years and it works great, and also has daily scheduled task updates and a virus def update.