Girl in next cube got a message on screen about system being infected with W32-RPC virus, but I don't think it came from Norton Antivirus we have installed. She clicked the pop-up and when she subsequently declined to download some file, the machine hosed. WinXP Home comes up in boot menu, but no matter what I choose (Normal, Safe Mode, Last Known...) it always reboots within seconds and comes back to screen. Any idea what's going on?