It's not a shutdown timer on all systems. Win9x can still run with the RPC service crashed, it just runs like crap. Basically, the worm finds an open port, sends a falsified HTTP header, and overflows the buffer, allowing code to be executed in the RPC. This allows the virus to copy itself in your machine. NT crashes, 2000 and XP give you a timer because the RPC was tampered with. If you have problems, change the RPC recovery to ignore untill you dl the patch from windows update. There is a patch for all versions of windows 9x and above. Just DL critical updates and allow the machine to install them. After that, set the RPC back to how it was. (You find the RPC in your services under computer management in 2000/XP, not sure about 9x)
After making your machine momentarily rape proof, it's time to make sure the virus doesn't spread elswhere. Find a virus scanner. I suggest Grisoft's AVG, it kicks ass, and it's free. It also makes very short work of this asshat worm. Make sure you dl a free firewall like zonealarm and prevent further infections as well. The worm is very active right now, so removing it without applying a firewall is useless, you'll be infected again in a few minutes.