CMOS Memory Size Wrong

  The Real Fizz 09:55 09 Oct 04

I am using Windows XP which has been getting stuck when booting up. I get;
AMD Athlon (tm) Processor - 1200 Mhz
Checking NVRAM
393216KB OK (16MB shared memory size used)
CMOS Memory Size Wrong
Press F1 to run SETUP
Press F2 to load default values & continue.
I have been pressing F2 and everything appears to work, only to happen again the next time!
I also noticed yesterday that the date and time had changed by itself.
Any help gratefully received but keep it basic please!!!

  Forum Editor 10:07 09 Oct 04

by replacing the CMOS battery, or even by resetting the CMOS state.

The battery is the round silver one that's about the size of a 10p coin - usually it's a CR2025 type, and available from pretty well any supermarket's bettery stand. Just open the computer's case and take a look at the motherboard - the battery is very easy to spot. Just ease it out of its retaining clips and slip the new one in - make sure to get it the same way up as the old one.

Alternatively you could slip out the existing battery, wait for a couple of minutes and slip it back again. This action will drain the CMOS state and when you boot you should automatically load the default. Best to put in a new battery while the case is open though.

If that doesn't fix the problem come back here for a rethink.

  The Real Fizz 10:14 09 Oct 04

Thanks will open it up and have a look for what type of battery I need and try and replace it. As I mentioned, my computer skills are very basic, can you just tell me whether I have to take any safety precautions when opening up the back??

  Forum Editor 12:22 09 Oct 04

1. Turn the machine off at the mains, but leave the plug in the socket.

2. Open the case and take a look inside. Spend a few moments getting your bearings before you touch anything. You'll see the hard drive(s), floppy drive (if fitted) and any CD drives in their cradles, with various leads and ribbon cables running to them from the motherboard. You don't need to interfere with them in any way, so leave well alone. The motherboard is the large sheet of plastic resin material covered in tiny circuits and chips. It will have other components connected to it.

3. Look for a small, shiny circular disc about the size of a 10p coin - that's the CMOS battery, and there's nothing else like it on the motherboard. It will be held in its socket by a spring-clip.

4. Ease the battery out - it's OK to use a blunt knife blade or small screwdriver if necessary, but it will come out quite easily - do not use force, do it gently. Make sure you're aware of which way up it is - these batteries are positive on one side and negative on the other. There'll be a + sign, usually on the side facing you.

5. When you have the battery out, check the number - I think it will be CR2025 - and buy another one - don't worry about the make, it's the number that's important.

6. By the time you get back from the shop the CMOS state will have discharged. Fit the new battery, and replace the case. Check carefully before you close the case - it's easy to pull one of the ribbon (IDE) cables out of the motherboard connector, or to loosen one.

Now reboot, and see what happens - you should see the computer start normally as the CMOS settings revert to default.

  Fruit Bat /\0/\ 12:57 09 Oct 04

When new battery fitted you will need o reset the date and time hardisk types(may auto recognise)n processor type etc. to get the best out of your machine. click here

Just tell us the make and model of your motherboard and chip fitted and we can advise on the settings to make.

  The Real Fizz 22:04 16 Oct 04

Went out and bought CR2025 in anticipation of earthing myself and then opening up the case. (I must admit to being a little nervous!) Unfortunately the battery turned out to be CR2032 but did a bit of light dusting whilst I was in there! :)
Unfortunately nothing had changed once I fitted the new battery and still telling me that my CMOS memory is wrong and I have to F2 to default settings each time I boot up.
Thanks for the help but any other ideas???

  The Real Fizz 10:16 17 Oct 04

Sorry, spoke a little too soon and does now seem to be fine with the new battery. Thanks for all your help :)

  The Real Fizz 10:17 17 Oct 04


This thread is now locked and can not be replied to.

How to watch Windows Event live stream, live blog | Microsoft event live stream: Watch Microsoft…

1995-2015: How technology has changed the world in 20 years

This amazing app turns your iPad Pro into a Cintiq

iPhone 7 Plus review: A superb big-screen phablet, but the price tag's enormous | iPhone 7 Plus…