As per Greymist's comments...
From memory: the majority of the code leaked was apparently from MS Paint (you know, the program that lets you draw dodgey pictures, it comes by default with all versions of windows), so you might find that people find a few exploits for that.
Anyhow, as a general rule: you should ALWAYS check for the latest "critical updates" and "service packs" from the Windows Update site.
Two ways to access it:
Click on Start, then Windows Update, or
From some versions of Internet Explorer: Click on Tools, then Windows Update.
Additionally, you should also run an Antivirus program,
McAfee and
Symantec Norton Antivirus, and use the inbuilt "virus definition update" (aka LiveUpdate in Symantec products) to ensure you're protected against the latest viruses.
If you don't update your PC and Antivirus Software regularly (once a week isn't hard, and you can schedule the software to do it automaticly), then you may as well not bother at all.
EVERYONE using a Windows based PC should be following these basic precautions whilever you use an internet-connected PC, regardless of whether you THINK you're at risk.
For those of you who think you're never going to be infected, you should be aware that many of the newer viruses simply require you to be connected to the internet to be infected (assuming you dont protect your PC).
Additional precautions you should take:
(1) If you recieve an email with any sort of attachment, and you wern't expecting it -- reply to the sender asking them what it is. Often a virus will send a copy of itself to all the people on your "address book" (aka Contact List), and the sender will not have any knowledge of this. A quick email can save being infected by a virus.
(2) If possible, configure your antivirus software to scan all emails you recieve, and files that you open. If you can't do this, or don't know how -- there are usually in built "help files" with the software, if you're still not able to do it, you might consider asking a local techie to help.
(3) Update your antivirus software regularly. Check the help files or ask a techie how to do this.
(4) See #3
(5) Incase you blinked or skipped past the previous points: Update your Antivirus Software regularly.
(6) Yes, I'm ranting, but I can't say it often enough: Update your Antivirus software regularly!
- Your local ranting mostly-friendly psychotic techie.