Bios?

[FarmGirl]

I'm rebuilding an old tower- replacing everything but the motherboard, floppy drive, and modem.
The reason she's been out of commission was viruses. Many lovely bugs riddled her insides until she died. I can't afford to let any slip through on this rebuild.
Is it possible for viruses and the like to inhabit the bios of a machine?

[TurkishMonky]

to have viruses actually in your bios would be extremely rare, but there are ways that they could possbly change settings in your bios, so you may want to check that out. (it is also possible that a virus could have scrambled up your bios, but that would make your computer not even come on...)

Usually, the bios will throw a warning that asks you whenever it's being changed.

If you are truly parinoid, and you have a flash bios updater, just build your computer once and update the bios to the newest one on the manufacturer's web site, then format C: and rebuild it again.

[Mithrandir]

I think updating the BIOS is a great idea, actually. I don't know of any bios borne virii, just fyi.