Computer won't boot when it was off for some hours

[madmalkav]

I have a weird problem with a computer and I'm completely lost.

When the computer is down for hours and I want to boot it, Windows won't boot. It will restart during boot process, complaint about files missing in windows/system32, ... after some tries, the computer will boot, and it will work flawlessly. Also, It will restart ok or even shutdown and start ok, and will only fail again when it is down for hours.

Any ideas what can be the problem? I tried to reinstall windows without success, memtest says ram is ok, seatools says hard disk is ok, ...

 

[gavinseabrook]

Seagate says the hard disk is ok, but there might be an issue where it isnt spinning up all the time. Does your BIOS always recognize it no prob?

 

[madmalkav]

Yeah, always recognzed without problem.

 

[raybay]

I would pull and reseat all cables, then run Windows in repair mode, unless it is a recovery/restore disc that does not have the repair option.
Another that often works is to remove then reinstall Service Pack 2, and to the updates over.