Have you tried virus scanning with Norton in safe mode? It may be able to remove the file if it's not active. Also, turn off System Restore (temporarily), before going into safe mode, as viruses can lurk there, and once removed, can be reborn when you next start your PC. To disable System Restore, right click your My Computer desktop icon, and select Properties, then the System Restore tab. Untick the box, to switch off System Restore. Don't forget to switch it back on again, once your computer is clean. You could also try
Spybot S&D, which can sometimes see stuff the others don't. Also might be worth trying
CoolWeb Shredder, in case it's a variant of that.