I have to confess that I refuse to take SP3.

My problem with it is that it locks you into IE 7 as a browser and the only way to solve it is either not to accept SP3 or if you did, uninstall it.
When IE 7 first came out, I downloaded it and kept it on my system for about 15 minutes before uninstalling it. For the work I was doing, IE 7 was making it twice long to do the job; what was easy for me to do with IE 6, turned into difficult with IE 7.
Having an Intel CPU, that was the turn off for me--the browser being foisted on me.
Because I knew that I wouldn't take SP3 due to it containing IE 7, I did some reading about what's in there, and most experts wrote articles saying that if you've always done all the Microsoft updates prior to SP3, it was really a compilation of all of the updates.
Had seen that plenty of people were having the continual reboot problem after they installed it and I don't think every one with that problem had an AMD CPU either.
Not sure if I'd take HP's advice on this. Knew someone years ago who had Dell and swore by it. Late one night a problem developed and they called Dell's support number. No idea what the tech was thinking, but he/she told them to be making a lot of reg edits.
The result was that the 2 systems they used for their business were totally useless.
When it wasn't working, they then called Microsoft CS and were told that everything Dell told them to do was totally wrong.
In order to get their information saved and get their systems running again, they had to pay through the nose for Dell to send a tech to their home (they worked from there). The tech salvaged their information--their disks had to be formatted--Windows had to be reloaded along with all of their business software.
I personally couldn't feel comfortable with the thing either, when Microsoft tells you everything has to be done in safe mode. They initially issued SP3, then pulled it, then issued it again. You'd think that everything that was wrong would have been corrected when it was re-issued.
http://download.microsoft.com/download/6/8/7/687484ed-8174-496d-8db9-f02b40c12982/Overview%20of%20Windows%20XP%20Service%20Pack%203.pdfWhat's In Service Pack 3
Page 4
"Windows XP SP3 includes all previously released Windows XP updates, including security updates and hotfixes, and select out-of-band releases."
Previously released updates, etc. that are included cover pages 6-10.
Page 12
"Windows XP SP3 combines all previously released performance. security, and stability updates. It also provides a limited number of new and enhanced functionalities, although it does not significantly change the Windows XP experience or bring functionality from newer versions of Windows (Vista) to Windows XP. The goals of Windows XP3 are to:
"Provide a new baseline for customers still deploying Windows XP, to help them avoid the inconvenience of applying individual updates.
"Fill gaps in the updates users might have missed by declining individual updates when using Automatic Updates, and to deliver updates not made available through Windows Update."