I have been considering doing this for a while now since my PC started acting weird a few months ago after a case dusting/cleanout (nothing too serious, but weird nonetheless). In my motherboard manual, it gives me two (seperate?) ways to clear CMOS: a) By shorting two pins on the motherboard (with diagram). b) Removing the battery. Will I need to do both or just one to clear CMOS? To clear CMOS by shorting the two pins, how exactly do I go about doing it? Do I just use a normal drive jumper to short the pins? I assume that I put the jumper on while the power is off, but do I then need to turn the power on? How will I know that CMOS is clear? There was a thread on this not too long ago that breifly looked at CMOS and it said that when you clear CMOS, you lose everything. What is meant by "everything"? Surely not the data on my HDD's? If I clear CMOS, is BIOS affected at all? Will I need to flash BIOS again after clearing CMOS? And finally, if I clear CMOS, would it be recommended that I remove any hardware such as PCI cards or HDD's before doing so? I will be reinstalling Windows anyway, but I'm hoping this will sort out any problems that might have risen in the past few months ie minor IRQ problems (see BSOD IRQ thread in general hardware forum for just one example). I'd be extremely greatful if anyone could help me out here. Cheers in advance!
Ist way: Power off the PC then disconnect the mains supply. Locate the CMOS jumper settings block (this should be close to the battery). Take off the jumper and you should have 3 pins the jumper block should have been on pins 2 & 3. Just remove that block from pins 2 & 3 for about 10 seconds - then put it on pins 1 & 2 for about 10 seconds - then finally, put it back on pins 2 & 3. The CMOS should now be clear. 2nd way: Power off the PC then disconnect the mains supply. Locate the battery and remove it for about 60 seconds then refit it. Do not use metal tweezers to hook the battery out!! You only need to use one way to clear the CMOS. You will not lose any data that has already been saved on your hard disks. I've never heard of a need to remove any hardware whilst clearing CMOS and it's never affected my hardware when I've done CMOS resets. A CMOS reset from my experience, has put the BIOS back to its default settings. It might be wise to run the motherboard driver CD to reinstall essential drivers again - I have done this and have had no problems. I'm sure other will advise you on this latter point. Good luck!
no, just one, ether way you choose ether remove battery for 10 seconds or move the jumper from pins 1 & 2, and place it on pins 2 & 3 for 10 seconds then move it back to pins 1 & 2 yep, but there will already be a jumper there after clearing CMOS no, clearing the CMOS only resets mobo settings (and date & time) your HDD data will be unafected CMOS & BIOS is the same thing, some people say CMOS (mainly "old school" enthusiasts) and some people say BIOS BTW: it is NOT a good idea to flash the BIOS (if anything goes wrong during a BIOS flash - your mobo is tuned into an expensive paperweight (dead - for good)) a BIOS flash is just fancy way of saying update no then you need to enter the BIOS and set the date & time (and possibly disable the CD as first boot device) all done np glad to help
Clearing the CMOS simply means that you put a normal jumper of the CMOS pins to create a connection between them and wipe off the BIOS settings. These settings are like the time, boot order, and overclocking settings you may have adjusted. It basically puts it back to the default settings, which may or may not be suitable. You shouldn't have to reinstall any drivers after a CMOS clearing.
