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I am using an HCL desktop system (Core 2 Duo, 1 GB RAM, Windows XP SP2). While booting I got the following message.

CMOS check sum error. Press f1 to continue

When pressing F1 it is working fine.

I checked some other sites for this problem. They suggested to change the CMOS battery. I have changed the new battery. Still I have the problem. How to resolve this problem?

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Try resetting the BIOS to defaults. –  Karan Oct 15 '12 at 6:27
    
try upgrading the BIOS to the latest version. –  bettsy583 Oct 15 '12 at 6:30
    
is possible to update the BIOS via offline? can you please share the steps? –  Haridharan Oct 15 '12 at 6:54
    
@Haridharan If you mean reset it offline, yes but it is motherboard spcific. Go download/find the manual for your motherboard and you are looking for something called CMOS reset. It usually involves moving a jumper on the motherboard. –  Scott Chamberlain Oct 15 '12 at 7:49
    
Little bit confused before updating the BIOS. Can you please help me. detailed system info : MainBoard -> Gigabyte 945GZM-S2 , Chipset -> Intel i945G/GZ , Processor -> Intel Core 2 Duo E4400 @ 2000 MHz , BIOS Version ->FC HI, BIOS Date ->04/24/2007(mm/dd/yyyy) . While downloading the BIOS update there are 3 revisions and each revision contains multiple BIOS revisions. I can find the FC version in rev 2.1 and its release date is 01/12/2007(mm/dd/yyyy). it is less than my bios date. Which one I have to download? gigabyte.in/products/product-page.aspx?pid=2425&dl=1#bios –  Haridharan Oct 22 '12 at 8:56
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2 Answers 2

up vote 2 down vote accepted

Update your bios date and time after you have changed the battery. If not, try to make sure your battery is properly fixed.

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+1 I agree, this looks like the symptoms of a dead CMOS battery. –  Scott Chamberlain Oct 15 '12 at 7:49
    
Little bit confused before updating the BIOS. Can you please help me. detailed system info : MainBoard -> Gigabyte 945GZM-S2 , Chipset -> Intel i945G/GZ , Processor -> Intel Core 2 Duo E4400 @ 2000 MHz , BIOS Version ->FC HI, BIOS Date ->04/24/2007(mm/dd/yyyy) . While downloading the BIOS update there are 3 revisions and each revision contains multiple BIOS revisions. I can find the FC version in rev 2.1 and its release date is 01/12/2007(mm/dd/yyyy). it is less than my bios date. Which one I have to download? gigabyte.in/products/product-page.aspx?pid=2425&dl=1#bios –  Haridharan Oct 23 '12 at 8:39
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There are generally three causes for this message:

  1. Device connected/disconnected or changed settings (CPU overclocking faliure, new hard drive)
  2. BIOS time is wrong/unset.
  3. All settings wiped due to dead battery.

References:

http://www.tomshardware.co.uk/forum/278461-12-cmos-checksum-error

http://en.wikipedia.org/wiki/Nonvolatile_BIOS_memory

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