BIOS checksum bad; Date & time not set

[shadowfax123]

I am having a strange problem lately! When I start my computer, Windows does not load as usual, instead I get a prompt as follows, "BIOS checksum bad; Date and time not set; press F1 to run set up; press F2 to load default value and continue" here when I press F1 I enter the BIOS setting and I see all the settings are set to default and I have to set the date and time as well. After I save and exit the BIOS Windows loads normally and I do not face any problem during the session. However, when I start the PC afterwards I have to undergo the same problem every time.
It seemed to me that I had to change the motherboard battery to take care of the problem, so I did but the problem remains. I also flashed the BIOS with the latest BIOS update if it could help but no good outcome so far.
My desktop PC consists of an Asus motherboard, an external PCIe graphics card and I use Windows xp SP2. I wonder what could be the problem! Looking forward to your replies.

 

[Aneesh@4GHz]

How old old your pc? If more than 3 years,It may be the cmos battery problem,change the battery and check it again.I had the same problem with my old intel D101GGC,and it worked aftr the battery change!