It was the Prescott heating up (I think)-problem looks solved! Hello guys: I think the problem I had of random BSODs looks like it has been solved. The new thermal paste helped-and that got me thinking-after I did some research, I realized that my Prescott 3 Ghz HT processor may be the one heating up and crashing the machine-because the same problems happened under Vista as well. Even though I had bought a new mobo, instead of swapping the old one out, I bought an OEM Pentium D 940 (Presler-Dual core 3.2 Ghz) from Tiger Direct for $109 and installed it with the paste yesterday and would you believe it?-No crashes -system running heavy loads for over 6 hours now -no BSODs at all! Vista and XP running great-with the old mobo itself! Hope this helps someone-I will keep the post alive-I still want to see how the machine does after a week...:hotbounce Update-after more than 10 hours with multitasking-not even one crash-the fans are running a lot cooler as well (just by tactile sensation on the case side)-I would stay away from the Prescotts unless you can leave the case open I think-the Presler Penium D is great and the Dell A03 BIOS recognized it w/out any problem and XP and Vista did not ask for reactivation also! Thanks to all who volunteered thier help for me... Final Post-success at last! 5 days after change in processors and not a single crash!!! Final verdict-guilty of heat related injury-Prescott 630 HT processor-condemned to sit in solitary confinement!! Cheers! over and out! June 9, 2007-Fellows! The machine is running fantastic-yup-not a single crash since the processor change. I'm lovin' it!!!