Did you have the Blaster Worm?
Per Rick Rogers: Remove it from your system
a. Start the registry editor program, regedit, by going to Start
| Run, and typing REGEDIT
Navigate to HKEY_Local_Machine\Software\Microsoft\Windows\Current
Version\Run by clicking the plus signs next to each of the
folders in the left hand pane. When you get to the last of them,
Run, click the word Run itself.
Find an entry called "Windows Auto Update" on the right side. Right-click it
and delete it.
b. Do a Windows search for msblast, and delete all files found.
The worm is now gone, and won't start again the next time you boot. But if
that's all you do, you can get reinfected just as you did the first time.
