Building this machine for the In-laws. It has been running fine for 2 days now. I came yesterday to find the screen saver not working, so I moved the mouse to find the system was locked.

After reboot, I got a black screen saying there was a file missing from Windows 32, and that I had to restore the file.

I rebooted again. Now all I get is a CMOS checksum error at POST.

The board is a Epox 8KHA+(my old board). Its less than 1 year old. I have checked everything else.

Could the battery be dying? It doesnt seem to matter whether the battery is in or not. It still boots to the same error? What would cause this after idling fine for a couple days?