I thought I'd share this in case you haven't heard, but Microsoft has released a free virus checker called Security Essentials.
I'm a long time Microsoft OneCare user and I was little upset when I heard MS was dropping the product. I really liked OneCare compared to other virus checkers.
At any rate, MS has put out this new product. I'm not sure how good it's going to be but the price is right and it's worth a try. I've installed it on my laptop and I'll be using it when I upgrade to Windows 7 later this week.
The link to the virus checker is
http://www.microsoft.com/Security_Essentials/
John