MY COMPUTER JUST DID THE SAME EXACT THING THIS MORNING...ABOUT 2 DAYS AGO I REPLACED THE VIDEO CARD PCI TO AGP THEN RE-INSTALLED WINDOWS XP PRO. WORKED FINE FOR 1 WHOLE DAY SHUT IT DOWN THIS MORNING THE SAME SCREEN WITH MEMORY TES!!! WHAT CAN IT BE P4 3.4 W/ 4GB OF MEM 256 HD AGP VIDEO LANPARTY MOBO THE MOBO BEEPS HARD DRIVE RUNS FANS WORK FREEZE UP ON START UP HELP!!!!!!!!!!!