I have a laptop that I suspect has a virus in the CMOS that keeps writing to the MBR every time I boot up. Why I came to this conclusion is a long story, if you're really curious I can tell you but I'd like to rule this out first....

Anyways, I want to totally flash the CMOS. Kill it completely.

My question: Do BIOS upgrading utilities accomplish this? Is there a difference between using these utilities and actually flashing (i.e. using the flash jumper setting or removing the battery?) How about from a virus point of view? It seems to me that it is flashed. Worst of all, it's my aunt's compaq and I can't tell what the software does.

I also want to know the best route to a clean XP install that will avoid any virus transmission to the MBR. My plan of action: FDISK the hell out of everything, reboot, flash BIOS, and clean install XP.