Random boot problem

[Gwyn]

Hi guys
about every couple of months I get this problem
my pc boots for about 5 seconds and then powers down but still spins slowly. After clearing the cmos it works fine for another couple of months.
The pc is not overclocked
I was wondering if there could be an underlaying problem there somewhere.

Thanks

 

[luminous]

Cmos chip could be flaky by the sounds of it,try newest bios update

 

[Gwyn]

I will give that a go
thanks for the Suggestion