Asus motherboard - CMOS CHECKSUM error (m2n-e)

[netrate]

This just recently has been happening - when I boot - I get the
"CHECKSUM error - press f1 to continue or f2 for setup"

Now, here is what I have tried
1) re-flash the bios
2) Flash to an older version

Both times it boots fine, but when I power down and power back up - the CLOCK and CALENDAR for windows is screwed up and the CHECKSUM error occurs.

What should I do?

 

[GhislainG]

If you lose your BIOS settings when you power off, then the first step should be to replace the battery.

 

[netrate]

Ok, what kind of battery will do?

 

[GhislainG]

Your motherboard uses a CR2032 Lithium battery.

 

[Zorg]

Yup, new battery from the drugstore. Make sure you don't put it in upside down. Most mobos are idiot proof, but not all.