Computer randomly freezes in beginning of usage

Hello!

I have priviously been helped on this forum. The problem then was, what I thought was temperature problems, indeed a defect memory. That story can be read here:

http://www.sweclockers.com/forum/55-intel/876760-temperature-...

Now the story continues on when I got new memorys.

Problem description:

The computer normaly succeeds to start, but afte a minute or two it freezes. It does freeze under start up to. What's on the screen will proceed to be showed until the computer restarts automatically. The sound will also freeze to be the tone it lastly had, so typically a 'beep' sound if music was played. This can occur like 3 times in a row. It all appears totaly random.

As indicated above, it stops freezing after a while and the longer the computer stays on the smaller are the risk of problem! (If the computer have survived more than 5 minutes it will be stable!)

So therefore I think that the temperature is not an issue here. The problem does not either occur when I stress the computer.

I have tested all combinations of my 2 memorys in the slots. One at a time (in both slots) and both (swaped in the slots). It seems that the system works better if I just use one memory slot. Then the problem rarely appear, but with both slots in use the problem appear more often than what it is not appearing.

I did run the Windows memory diagnostics tool, without finding anything.

The computer:
OS: Windows 7 Professional (64bit)
MoBo: DG45ID
CPU: Q9400S
RAM: Corsair XMS2 DHX minne - 4 GB ( 2 x 2 GB ) [800 MHz]
GPU: Radeon 4770
HDD: Samsung SpinPoint F1
PSU: ETASIS 300W

I hope someone has an idea! Thanks!

Reciver: I have not tried to remove the DVD-rom. I don't think that's the problem, but it might be worth a try. Cleaning the "comp"; you must mean "components", right? I have no idea how do clean those succesfully without causing new problems All bios are up to date and should be able to handle up to 32 GB of memory (I have 2+2 GB).

Oneone: The memorys are in the right slots. There is two pairs of slots, a blue pair and a black pair. They should be in the blue pair and they are. I use the HFX Classic chassis which is based on passive cooling, so there are no fans! Remember that the computer works perfectly after some minutes of usage. I definitely think the problem is hardware related The computer have never freezed during bios operations, it's when the windows logo appears (loading the OS I think) that the problems seems to start. So maybe it's a hardware problem within the moderboard or/and the memorys? Dust removal might be good?

Quim: "probably something as weird as the problem itself": I think you're right! That's why I seeking the answers on this forum

Thanks for the answers!