Hi ,

I've just been looking at a friends computer , she told me it had been running very slow ,etc . The pc is a socket 775 dualcore running on MSI P4M900M3-L (MS-7387) motherboard , VIA® VT8237S chipset All graphics , LAN , sound , etc are onboard . I uncabled one of my dual monitors using normal analogue output . Cleaned the heatsink fan , etc and booted the pc . It took 4 cold boots before I could even access the bios screen - all card readers , hd's etc were read by the bios but with the well known bad checksum error . I had a spare cmos battery which i replaced with the cmos battery from the pc , I'm not sure whether it works as it's from an old pc , still nothing , no beep errors but no power went to the keyboard and no boot to bios screen on the monitor . I cleaned the memory stick and swapped the casing slot , rebooted , no beep error but still no graphics . I installed my old ATI HD9600XT , which without drivers should have worked as an analogue PnP video card , still wouldn't boot to the bios screen .

Would I be correct in assuming that replacing the cmos battery with a new battery would solve the problem ? I know some lithium 3v batteries don't last as long as others and that they can lose charge even if mishandled . I don't want to mess about resetting bios etc as it's not my computer and I'm loathe to even mess to that extent on my own personal pc's

Would I be correct in assuming that replacing the cmos battery with a new battery would solve the problem ?

That's a good possibility as that will reset the BIOS. The key thing to remember with pulling the battery or using the CMOS reset is that must immediately boot into the BIOS Setup Menu, set the date and time, verify the drives, and Save and Exit to boot normally. If you don't save the settings, next time the system boots it will not find the hardware it expects, and can give the chksum error.

I would also want to ensure the PSU is good - either by having it properly tested, or swap in a known good supply, with an adequate power rating.