Won't change bio setting

August 13, 2009 at 00:02:40
Specs: Windows XP
I need helps!!!! My computer has a problem with CMOS check sum bad error. Whenever i turn on I have to hit F1 or F2 for set up or to load windows.

Other problem is it won't change bios setting like first boot, boot sector virus protection etc. When I change the boot sector virus to "Enabled" and save it, it will go back to Disabled. And when I change the boot priority to CD-Rom, it goes back to Hard drive boot priority. Could it be due to virus? I bought Reg Cure for $39 and it did not solve the problem.

I would appreciat any kind of help.

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August 13, 2009 at 00:12:03
I don't know why you would buy "Reg Cure" since it has nothing to do with the registry (and therefore nothing to do with the operating system).

Anyhow, the first thing you should try is finding the option in the BIOS settings to "Reset to defaults". Do this, so that everything in the BIOS gets reset. Then go back in and try configuring things to your liking. If they don't stay set that way, download the latest BIOS firmware for your motherboard, and flash the BIOS.

-Ryan Adams

Free Computer Tips and more:http://RyanTAdams.com
Paid Tech Support: Black Diamond

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August 13, 2009 at 05:45:02


I am not saying buy the 1 on ebay, I am just showing you how it looks and the approximate price


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August 13, 2009 at 06:01:35
Try trplacing the CMOS battery. Inability to retain setting is a sure sign the battery is on its way out.


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Related Solutions

August 17, 2009 at 07:01:49
Hi guys, thanks for your input. I have once exchanged the CMOS battery with my other computer. The other one has no problem with that battery. So I believe I need to upgrade bios. I am researching how to upgrade it. If you know an easy step to upgrade bios, your helps will be much appreciated.

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August 17, 2009 at 07:34:36
I doubt that you need a BIOS update.

Are you using a power strip or some other method to fully interrupt power to the PC when you shut down?

If power to the PSU is continuous the battery is then unnecessary. If however, you are stopping power to the PC then the BIOS will revert to defaults each time if the battery is weak.

A sure test of this is to check the date and time in the BIOS screens when you first boot. If they are wrong then the settings are not being held.

Are you saving the changes (F10) when exiting the BIOS screens?

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August 18, 2009 at 08:44:39
Thanks for the reply. This discussion is about a desktop computer. The date and time in the bios screen never change however, the changes I made, such as CD-Rom boot priority, Anti-virus protection to "Enable"etc. change even though I hit F10 to save the new setting.

I asked how to upgrade bios to the manufacturer (Acer) and they want money to tell how since the PC expire its warranty.

I still have a belief that upgrading bios could solve this "CMOS check sum bad" problem. Any advise is appreciated.

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August 18, 2009 at 09:28:42
>> I still have a belief that upgrading bios could solve this "CMOS check sum bad" problem. Any advise is appreciated. <<

I am afraid you are working on a mistaken belief.

When you save the BIOS setting they are saved to CMOS memory. A checksum is calculated on the data and that is also saved to CMOS memorry.

When the computer boots again it calcuates the same checksum from the information stored in the CMOS memory. If the Chechsums match everything is fine. If the CMOS memory has been corrupted becuse there is no power to maintain it, the Checksum is incorrect and you get the error.

The CMOS checksum has nothing to do with the BIOS codes which is in ROM and retains its contents without power. It is virually impossible to corrupt BIOS memory unless you do something silly, like a bad flash.

When you checked the battery in the other computer did you remove all power to make sure that it was working and not just close down and re-boot. If that is all you did then the battery was not be put to the test.

If you are absolutley certain it is not the battery you have to be looking at some other reason they the CMOS memory is not retaining its settings. It may be that the CMOS memory itself is faulty in which case its a new motherboard or possibley a new BIOS chip as the CMOS memory is contained withing the BIOS chip.


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August 23, 2009 at 22:05:50
Thanks again for your valuable input. Today I bought a new CMOS battery and installed it. The same problems occur. Is there way to replace bios chip? Or will upgrading bios solve the problem? If so how do I upgrade? My motherboard bios is Megatrend and it doesn't have function key to flash bios and update. Any help will be greatly appreciate.

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August 24, 2009 at 04:09:22
Are you sure the battery is not installed upside down?

Also, some motherboards have TWO BIOS chips on them. One is for a backup. Additionally, some have a jumper to LOCK the BIOS.

Post the exact model of the board.

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August 24, 2009 at 07:37:24
This is Acer Aspire M1640. The battery was installed correctly. Changed Sata hard drive connections, removed IDE cable to make sure I/O connection issue or not. Still there CMOS check sum bad and still can't change settings.

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August 24, 2009 at 11:06:04
You can't change any settings or they won't retain?

Has the BIOS been flashed.

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August 24, 2009 at 23:29:27
I can change buy it can't retain. When I press F10 to save the changes and even after it starts, it can't boot directly. I have to press F1 for Set up or F2 for to load windows. The changes have been reset to the previous setting when i hit F1 again.

I am not the original owner and I don't know the bios have been flashed or not. The computer/CPU seems to have been over clocked by previous owner or manufacturer. The CPU is Intel dual core E2100 and the memory is PC5300 (667 Mhz). The current bios version is the oldest of the manufacturer website.

Seems like upgrading bios is the only choice I have. But i need to research how to do.

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