I have purchased a bunch of new parts for my PC.
 
I am having issues with my PC freezing/Restarting. My PC was freezes up at least once a day. As of late it restarts about every 30 minutes.  I have replaced all of the following: the PSU with a Coolmaster 500, the MoBo is ECS PA1 MVP (V2.0) The CPU is a Pentium D 3.0 925, 2gig Ram. I went out an bought a fan for it, and is working at Temps of 30c - 37c. I have changed the heat paste and added new stuff.  When it freezes/restarts I am just usually surfing the net. CPU usage is very low at the time. I am running Win XP Pro. I formatted when everything was installed. Can anyone tell me what may be causing this. Everyone that I speak with so far is placing this on the Motherboard, I would hate for this to be true as this is the first ECS that I have purchased and may be the last. ECS has not been any help as well.  

It could easily be your RAM.  Try one stick at a time and see what happens.

yep sounds like ram to me as well. try what  jtt283 said

Thanks I will try some RAM testers; any recommendations would be great as well.

mmustang69 you could us memtest on them,but would try just one stick first,to see if one of the rams is bad.also what kind of ram is it?

It is Buffalo 667MHz  DDR2.  I did do the memtest and came up ok.  I did however leave both sticks in and only ran it through one pass.  Should I have done this differently.  I have been in communication via email with ECS and they say that I should update my BIOS.  Now I have never done this and don't really want to create a door stop.  Do any of you have any ideas if the Bios would cause this and were would you go from here?
 
Thanks for all the help, great forum..

well use memtest to test ur ram
 
well i would recomend to leave the memtest running overnight with both sticks. that would be about 15+ pass
 
you can also try reflashing ur bios by using the jumper on the motherboard.  READ USER MANUAL - one mistake and u get a dead motherboard
 
update as they told you, after reflashing the bios. some times bios updates do fix problems. READ USER MANUAL -one mistake and u get a dead motherboard
 
gl

What kind setup do you have for the rest of your computer? I.e. how many HDD and what graphics card, etc. Make sure your computer isn't drawing too much power from the PSU as I have seen this happen to a friend of mine's computer, random freeze/reboots after he put in a TV decoder that requires a lot juice.  What software do you use to measure temperature?  I've found some of the software that came with mobo's to be off up to 15 degrees (like the uGuru from Abit's latest IX38 board), I use CoreTemp.  RAMs can be a problem but it would usually be detected in boot up.  Read up on the latest BIOS that your mobo has and see if there were mentions of this type of problem being corrected, but again it doesn't really hurt in most cases to upgrade to the latest BIOS anyway, it's not hard to upgrade BIOS just need 1 or 2 floppy disks and flip a jumper in the mobo couple times.

Thanks to all, "miamirain"  I have a 250gig and 80 gig HDD. 2 DVD rewritibles.  ATI Radeon 1300 pro PCI Express.  The Powersupply shuld be enough to run everything fine.  The software I used was speedfan, as well through the BIOS.

Yeah doesn't sound like what you have would draw more than what the 500W can handle, if you say the memories tested out alright I'd flash the BIOS to version 1.2 (latest according to ECS site) as the next attempt, seems it has updated some support for certain processors.

Ok, I have had the BIOS updated and formated again.  Placed 1 80 gig HDD and did all the testing, no issues.  I placed the 2nd 250 gig HDD and went and started to install old Programs Ex: Nero, Office.... everything working fine.  Then started to multi task while surfing.  Open 2-3 browsers and surf.  While open one page and then refreshed another froze up.  Restarted and tried the same thing worked fine.  Went back a few hours later and tried again and the PC restarted.  Last night left the PC on and it restarted through the night.  Any Other Ideas??  This is very discuraging as I spent $550 for the parts and $60 for a Tech to look at it and to say all seems well.  Would it be possible that its something to do with the location?  Power outlet or anything like that?  1 last thing, on the ECS page states the CPU's that it supports, and I do not see the Pentium D 925 chip, would that be the issue.