If you are wondering how to get rid of the Sasser worm, you need to go to this website and download the patch : MS Patch Download Center

Then go to this site and download the removal tool : Symantec Security Response - W32.Sasser Removal Tool

Run the patch, then run the removal tool.

You also need to go to the Windows Update Site and fully update your system with ALL of the critical updates. This may force you to also upgrade your browser to MSIE 6 (with patches) and perhaps apply one or more Service Packs to your system. All this will take a LONG TIME and many reboots.

Microsoft. Gotta love 'em.