Hardware

So what you're saying is, the computer doesn't boot, at all, ever, or even react, at all, ever, no matter what you do with it. It may be dead dead, not just dead-video dead. I don't suppose you have a POST card.

What is the OS and version? If it is unix/linux then it probably will boot without a video card (assuming that the motherboard/cpu/memory is not damaged.) Can you ping it?
Does the speaker beep? if so count the beeps and check the BIOS manual for that motherboard.
Find a DOS/Win95/Win98 boot diskette and try to boot from it?

When did that change? Having no video used to be a beep-code level error(and still was for anything but motherboards designed to be standalone, as far as I knew).

A computer that doesn't even POST could hardly be expected to boot from floppy.

ideo problems Dell Cpx? 850 PIII laptop
Customer has a 850 mhz PIII Dell laptop. The video gives up on it by the next day after he took it back each time. I've uninstalled the drivers and put the most up-to date ATI M3 drivers on. The ram checks out fine, the rest of the machine works wonderfully, it has no viruses or spy ware that I can detect. He said it happens in the mornings so I'm wondering if the CMOS battery could be dead. Could a dead battery cause no video to come up in regular mode?