Problem with WIN32.TROJAN.PUPER.D

I was surfing a few nights ago when I noticed that the machine seemed to be working much harder than usual, until finally a message popped up telling me that memory resources were critically low and that I should close some open applications, which was odd since Explorer was the only thing running. A few seconds later, the machine froze altogether. I shut the machine off and tried to reboot. In the course of the reboot, a message briefly appeared that configuration changes were being made, which I didn't figure could be a good thing. The reboot then proceeded as normal, but hung up at the point where the desktop icons would normally appear. I rebooted in safe mode and ran AdAware, and it found WIN32.TROJAN.PUPER.D. I quarantined the virus and tried to reboot. I again saw the message about configuration changes being made, and the machine again hung up right before the desktop icons would usually appear. When I use ALT-CNTRL-DEL to bring up the task list, the only thing there is "Msgsrv32 (Not Responding)". I can still boot up in Safe Mode, but a regular boot hangs up at the same spot every time. If anyone can help me out of this mess, I would appreciate it very much.

Thanks...