Randomly, my PC just give a blue screen and restart, at first i though it was the OCing causing the problem, I reset everything to default, and yesterday it happened again. It's really annoying especially when I lose unsaved work. What could be the reason?

My pc is:
-Q9950
-DP45
-GTX460 1GB
-4GB RAM
-HDD+DVD drive
-PSU: TT KK500

I considered 2 reasons, maybe they're not correct:
-Over heating.
-PSU failure. ( But I don't think so, since a PSU failure will shut the PC down directly. )

What could be causing the problem!
Well it might be a software problem.
My computer was running fine when I first got it,but after a certain time I had BSOD randomly as soon as I boot to windows,the problem was fixed when I re-installed windows.
Might be a memory thing, just change the memory locations (RAM), swap them, sometimes it helps
its could be your Ram, run each stick separately and run memtest86+ and let it run at least 2 passes and then try running with both sticks
it may also be your PSU , when your PC can't handle the power it fails(i learned that the hardway)
ir may also be your Graphics card, if you have another one try using it
it may also be overheating , watch your temps. and if their high clean your fans and replace thermalpast
you can also try resetting your CMOS and checking your capacitors if they are blown
Try to read what's on the blue screen it's usually helpful.
As ED said, what is the bsod msg?

It could be anything, from a corrupted install of any type of program to a hardware failing somewhere.
yeah you could read some parts of the bsod message
It might be drivers...first of all, try to update them (graphics driver + chipset driver + ESPECIALLY audio driver) by cleanly uninstalling them then cleanly installing them. Then run the system with normal use. If BSOD, then uninstall those drivers and run the system (yes you will struggle because you can't run high-performance applications, but try it anyways). If it's rock solid stable, then there is your problem.

A failing PSU will not necessarily shut down the system. This is because:

1) You may not even be running the PSU on full load.
2) Even if you were running on full load, the PSU may not have overload protection.
3) A PSU may provide unclean power: a lot of ripple, out-of-spec voltages especially when under load, voltage spikes and fluctuations, etc...these can all lead to graphical corruption, errors, BSODs, etc...

You also need to provide the scenario when the BSOD occurs.
Thanks guys, really helpful.
But here some more info that cancel some possibilities:
-Some times my PC don't start, just the power led is on, and fans on. After messing with the locations of the RAMs randomly it starts, after switching a lot, maybe to the same position.
-Avok95, you made me consider buying a completely new case.
-Over heating isn't a choice, yesterday it failed while browsing the net only.
-I reset the bios last time i faced the 1st mentioned problem, now it turns off after I got the blue screen directly, I'll change it.
-BUT: I don't know, maybe the blue screen will come tomorrow, after 2 weeks, sometimes it's a month without it. And sometimes, 3-4 times a day.

So what could make the first problem happen?!! Mostly when one of the two rams is in the first slot, it wont boot!!!
ILIA_93 wroteThanks guys, really helpful.
But here some more info that cancel some possibilities:
-Some times my PC don't start, just the power led is on, and fans on. After messing with the locations of the RAMs randomly it starts, after switching a lot, maybe to the same position.
-Avok95, you made me consider buying a completely new case.
-Over heating isn't a choice, yesterday it failed while browsing the net only.
-I reset the bios last time i faced the 1st mentioned problem, now it turns off after I got the blue screen directly, I'll change it.
-BUT: I don't know, maybe the blue screen will come tomorrow, after 2 weeks, sometimes it's a month without it. And sometimes, 3-4 times a day.

So what could make the first problem happen?!! Mostly when one of the two rams is in the first slot, it wont boot!!!
i had the same problem before when i first built my pc
then after MONTHS of diagnosing
it turned out to be the PSU because it wasn't enough to power the system and also because of the PSU my ram got corrupted.
now you have a GTX460 which consumes a lot of power and a 500W PSU.
lets say your 50W of the 500W weren't there so that means you were running your system on a 450W PSU with a GTX 460
Can you see where im getting at?
your PSU is under full load and is not being able to run the performance that your system is trying to give(causing it to crash)
i suggest trying another PSU or a lighter VGA
and also CHECK YOUR RAM
also i have never hear of thermal take having a PSU Called "KK500"
AvoK95 wrotei suggest trying another PSU or a lighter VGA
HAHAHA, WTF!!! Lighter VGA, are you serious, you want me to degrade!!!

I'll test the RAM, and try to give the blue screen a look.
ILIA_93 wrote
AvoK95 wrotei suggest trying another PSU or a lighter VGA
HAHAHA, WTF!!! Lighter VGA, are you serious, you want me to degrade!!!

I'll test the RAM, and try to give the blue screen a look.
i don't want you to downgrade i just want you to use a lighter VGA and see if you get a BSOD , if you don't than you need a new PSU
Memory is clean, and I'm not gonna spend 120$ on a PSU, while mine is running well, I prefer a random fail each 2-3-4 weeks, than pay 120$, and even not sure that this will fix it.
My guess is the board, will it cause such thing? Because of what I mentioned first, how can this happen!!! ( Starting PC failed, and then fixed by swapping RAMs positions ) Surely this is not the PSU.
Is vdroop enabled for CPU? If so, disable it, and see.

Also, you need to know the temperatures. Overheating could be happening even at idle, if the coolers are not attached properly.

Download Core Temp and GPU-Z. Set an alarm in Core Temp at a temperature slightly lower than TjMax (mentioned in CoreTemp). If Core Temp sets off the alarm then the system BSODs, there you have it. But then again an overheating CPU that reaches TjMax usually shuts down, but maybe it's becoming unstable at slightly less than TjMax.
It is the PSU!
You'll see in the end.
Ed wroteTry to read what's on the blue screen it's usually helpful.
If you can read that screen, you're dangerously fast.
Video record the BSOD then play it in slow motion :)
I had to do that once; it turned out that my antivirus was causing the problem (Bit Defender).
Georges wrote
Ed wroteTry to read what's on the blue screen it's usually helpful.
If you can read that screen, you're dangerously fast.
You're right, it happens sometime that the BSOD appears for a few seconds and then resets but in most random cases (no pattern) it stands there until you hit the reset button, which does not seem to be ILIA's problem.


ILIA from the few posts you made about your troubleshooting it sounds to me like a memory, or board problem.
Your PSU is weak, the minimum requirements for your gtx460 is 450W and your PSU is min:400, max:500 , I don't think it's the problem but I could be wrong.