I saw this on Yahoo, and with tomorrow being April 1st (D-Day for the http://en.wikipedia.org/wiki/Conficker worm) here is an excerpt that may help:
Your first step should be the tools you already have: Windows Update
, to make sure your computer is fully patched, and your current antivirus software, to make sure anything that slips through the cracks is caught.
But if Conficker's already on your machine, it may bypass certain subsystems and updating Windows and your antivirus at this point may not work. If you are worried about anything being amiss - try booting into Safe Mode, which Conficker prevents, to check - you should run a specialized tool to get rid of Conficker.
Microsoft offers a Web-based scanner
(note that some users have reported it crashed their machines; I had no trouble with it), so you might try one of these downloadable options instead: http://www.symantec.com/security_response/writeup.jsp?docid=2009-011316-0247-99, http://www.trendmicro.com/download/dcs.asp, or http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html.
Conficker may prevent your machine from accessing any of these websites, so you may have to download these tools from a known non-infected computer if you need them. Follow the instructions given on each site to run them successfully. (Also note: None of these tools should harm your computer if you don't have Conficker.)
As a final safety note, all users - whether they're worried about an infection or know for sure they're clean - are also wise to make a full data backup today. More PlayStation 3 News...