I just spent the last ten hours trying to remove a virus from my computer. I don't know how old this is, but I am reading up on it and it seems relatiively new. It is called the Microsoft Security Essentials Alert virus. It fakes you out by making a fake version of Microsoft Security Essentials Alert. Then it basically hijacks EVERYTHING that has an .exe file attached to it. You can't open ANYTHING! It is so aggravating. I used Norton and Spybot to pull certain parts of it out so that I could at least us my Run command. Then I ran 'msconfig' and did a selective startup until I was able to weed out the startup things it had put in my PC. Oh yeah, and the System Restore doesn't work either with it.
Makes for an awesome afternoon. I thought I'd warn you all to watch out for this thing.