Pc Freezes Or Reboots Every Week Or So

For some odd reason my computer will either freeze a few minutes after booting up, or during a manual reboot [ie: when I personally restart via XP's "Start" menu]. I can't understand why this is happening and would like to know what could potentially be the root cause of this.

The funny thing is my computer will work for a week or more and not even show any of these signs... I thought it could have been some sort of virus but my pc isn't infected when scanning with the ESET AV I subscribe to, or Trendmicro's Housecall. I have backup images of my hdd I made with Acronis, so I was thinking about rolling back to an old hdd image. Than today I go to boot my pc up and it froze during the bios screen which goes to show me that it doesn't have anything to do with my OS/Data hdd, or so I presume.

There are only two things I can think of that can be causing this.

#1 My PSU which is an Antec Earthwatts 500 model... Less than a year old.
#2 My ram which is a few years old

I've tried reseating every card on my motherboard a while back and making sure all connections are tight but that still didn't show any improvement. This has been an ongoing issue for over a month. I haven't asked about this online because I thought it would go away for some stupid reason. Just a couple of hiccups is what I thought, but now this problem is nagging me and I can't risk my pc shutting off or rebooting itself anymore. It's bothersome and can potentially harm my hardware by letting this continue.

There are no hums, no clicks, no pops, or anything weird coming out of my pc, psu, or hdd's. I see no swollen capacitors on my motherboard, or any signs of damage. What's STRANGE is the fact that once is freezes a couple of times or reboots itself [always within the same day once a week or so] it will run smooth without a glitch. & I can leave my pc on for days on end without it doing that. I'm scratching my head. I'll be running Memtest on my pc all night tonight to see if I get any bad results and will post a reply.


Thanks for the help my fellow friends!

 

I'd vote for a flaky PSU; if the RAM works fine for a week, it's pretty much ruled out by the freeze on boot problem.

You could try running the PC from a different outlet, strange things happen ...

 

PSUs are always suspect when experiencing random, system wide symptoms...

You might check out your Event Viewer, see if anything correlates time wise...

 

What should I specifically check for in "Event Viewer"?

Thanks guys

 

It hasn't happened in a few months... Really weird.

 

You probably shouldn't tempt fate by saying that, it could be dry solder joints in the PSU they can cause sporadic intermittent faults I've had to resolder a couple recently.

 

What do dry solder joints look like, & how do you know it's that?