MoRe: Unusual Restart

I've checked all the fans (including the one on the graphic card) and
they're running. I've dusted the boards inside too.

There are times when I can run the PC througout the night till the
next day without any problem. So, if it's because of overheating, how
come sometimes it overheats and sometimes it don't? I've monitored the
temperature and it stayed around 43 degree Celcius.. is that too high?

I'm now trying the memory test.

Please keep all your suggestions coming. I'll keep you guys updated
about my progress.

Thanks.