There is a worm out there that requires no user interaction and is self replicating.
What does that mean? You don't have to open an e-mail to get it. It shuts you down from the internet. Enabling a fireway slows the effects down. (It can eat up ram to the point of freezing your PC), and although it doesn't seem to destroy data on your PC, it will kick you off the internet after about 2 minutes. (IF that long)
Here's the fix.
You may think I am talking doomsday bullshit, but everyone I know has either gotten it or fixed it. Those of you that have accepted the regular windows updates may be exempt with a patch that came out a month or so ago.