Ha! An anti-virus virus! Reading the site Jeanie linked to, it seems like this worm kills the Lovsan virus then applies the Microsoft security patch and commits suicide when it thinks it's 2004.

Guest Andy, it looks like you just have to change the date to 2004, and reboot to clear the virus, then you can go back to 2003.

McGrath, Blaster affects only versions of Windows AFTER '98 (2000 and XP). Welchia only affects XP.