You most likely have a worm W32.Blaster.Worm
DISCONNECT the subject computer from any network IMMEDIATELY.
Install or enable a firewall IMMEDIATELY:
http://support.microsoft.com/?kbid=283673
VERY IMPORTANT to follow ALL steps, closing ports or installing the
patch is NOT enough.
Download the patch and regedit referenced in the article below.
You may need to do this at an uninfected computer and burn to CD or
save on floppies.
Each file is small enough to fit on a floppy.
Follow this to clean and protect your computer:
http://www.kellys-korner-xp.com/xp_qr.htm#rpc
After this is resolved prevent similar occurrences by installing ALL
Critical Updates from Windows Update.
Keep antivirus up to date and run at least weekly.
Install or enable a firewall.
