don't use pre-release versions when a software reaches final release.
Get WXP's SP2 update from here -
http://www.microsoft.com/technet/pro.../winxpsp2.mspx
But the RC2 in this months DVD is pretty good as well. If you want to get the full version, and have a licensed version of WXP, turn on automatic updates to get SP2 final - you'll have to download about 25 MB in that case (don't worry, Windows Auto-Aupdate will do it for you, just turn it on and see that you have the time/bandwidth for it).
Once you have either RC2 or final of SP2, you don't need *ANY* update or patch - you've entered digital-age nirvana (atleast for the next 6 months till a new worm for SP2 is out, LOL).
In your current version, just open a CMD, and type
to check for existence of blaster worm, and to clean it.