HELP! I have a virus... and its WAAAY out of my league

This virus is crazy. I was just watching a vid online, then my sytem goes to whack. All of a sudden, most of my programs that run in the background all disconnect from the internet, with bad data errors. I notice a new item on my tastbar, antivirus suite. I already use AVAST, and havent downlaoded anything in the last week or so. and only trusted things aside from that. All of a sudden, this "antivirus" program starts a "sweep" showing me critical viruses. At this point im freaking out. It must be like one of those online popups that fake being a virus scanner, but this is ON MY COMPUTER!. then, google chrome starts to whack out, EVERY PAGE I GO TO redirects to http://antivirus-armature.microsoft.com/...php?r=57.6 telling me to buy an advanced copy of this antivirus suite. Now I start to try and open programs to screencap whats going on. ABOUT 80% OF ANYTHING I TRY TO OPEN gives me an error telling me that X program has been contaminated by a virus and has to be shut down. Now im getting fed up and try to open task manager, and it closes the second I open it. System restore wont open, and I have never seen a virus like this. If anybody could help me, I would love you forever.

I wouldnt mind starting over, but I dont have my vista recovery CD, and I have lots of stuff on this PC that I CANNOT LOOSE.