Tl;dr version: The whole computer freezes under load or sometimes (apparently?) randomly. Issue got progressively worse over time.
The freezes in a little more detail:
Essentially it's like a stop-frame, whatever is displayed freezes along with the cursor.
If there's sound playing, it usually keeps on playing (I think I remember a whole song going on to the end then stopping without playing the next one.) and there's a very light/short stutter just as the freeze happens.
The keyboard stops responding altogether, not even the Num/Caps/Scroll Lock buttons change their status.
HDD activity sometimes keeps going on for a few seconds, then stops (I can tell by the HDD noise). The HDD activity light either goes off or just stays lit up forever.
All fans keep spinning at the exact same speed they did when the freeze occured.
A little bit too much about what I remember that happened over time:
To get this out of the way first, it's 100% not a software issue. It happened over different OSes, software configurations and BIOS setups. I have not upgraded or changed any hardware components.
This is an issue that has been tormenting me for a while, and it has definitely gotten worse over time. It used to happen only under really heavy load, like extended gaming in a hot room. Then it kept happening more often and more quickly (sometimes seemingly more randomly). I decided to try and fix it through a thorough cleaning of the hardware, as heat was most definitely a factor. It worked, everything was back to normal. Some more time passed, then it struck again. I did the same thing, all was well for a while then it started happening yet another time. This went on for a few more times, to the point where I gave up going through the whole cleaning process and I discovered that it would sometimes get fixed if I reached over and pushed the power connectors, RAM sticks, GPU and HDD cables into the motherboard more snuggly. I stepped into yet another freezing-fixing cycle until it wasn't effective anymore. Underclocking came into play. I dropped the RAM's frequency from 533 to 400 DDR2. Then the issue progressed and I had to drop the CPU speed from 3GHz, and I gradually went lower and lower down to 2.7GHz in order to keep the issue at bay. Now I got to a point where it wouldn't even load the OS without freezing if I set the PC to its stock clocks and default BIOS settings. One day I decided to go through a very thorough cleaning , reassembling and redoing of the cable management. I went as far as to open the PSU and blow out every speck of dust, and apply vaseline to every fan I could in the system. Then I did some testing, which I'm going to summarise as: Underclocked-OK, All stock-OK. Then this is where I may have taken a wrong decision, and decided to overclock. I went as far up as 3.3GHz on the CPU and however high the RAM went in consequence (The highest I've ever managed on this wreck, mind you) for a good half an hour of heavy stress, before yet another damned freeze. Back to stock. Was fine for an hour or so, then it froze. Then I was just forced to underclock little by little to the point where I am now. And now I can't really underclock any lower.
The voltages are anorexically low, and they've been this way for as long as I can remember. Maybe the readings are wrong, I don't know. Here's a SpeedFan screenshot (almost idle):
Due to my budget, I'd rather not build a new PC, and also I don't really have access to known working hardware to do tests with. I don't really know what to do. I could buy a (cheap) PSU, but my fear is that there could be something wrong with the motherboard or some other part instead and I'd have gotten a PSU unsuitable for an entire mobo+CPU+RAM+HDD switch (Yes, I'd have to buy all of those, and the thought of it doesn't delight me). I'm not confident enough to pull any triggers yet.
Maybe you can shed some light on this? I'm at wit's end. Sincere thanks if you took your time to read this.
Tiny update: (Won't let me edit the first post for some reason.)
Just froze again under heavier load. I had to reset the PC, only to be welcomed by a black screen with a thin, glitched-out horizontal white line across the center of the screen just past the boot-up animation. Everything was frozen as usual, and I had to restart once more, only for it to freeze again, this time at the logon screen. After 2 more restarts it eventually gave in and booted normally. Can you make something of this?
I'm having the exact same problem. However, im using a 9600GSO on a 250w PSU modified to hold a 6Pin power connector with 16AMPS on a single 12V rail. Games freeze during intense scenes. Keeps getting worse over time. I haven't turned the PC on in a week cause i'm too scared to fry it. I'm 100% sure it's the PSU. Games freeze and i have to manually restart the whole PC, Random stuttering in games and stuff like that. Same as what you experience. I'm guessing yours freezes when there's a lot of processing going on. Mine freeze when there are a lot of enemies on screen (Modern warfare 2, Resident evil 5 no mercy and dead rising) cause thats when both the PSU and GPU are at their peak power consumption levels and the PSU fails to provide the power. Save up for a better PSU! I've only got 10 Pounds left to go before i can buy the XFX 450w pro series PSU
sounds and looks like your undervolting the cpu.
go into bios and load optomized defaults and make sure your motherboard is compatable with windows 7/8/vista by enabling (hpet/high precision events timer) on older boards it must match the bitrate of your o.s so set it to 64 if your using a 64bit o.s
this is likely the cause of your whole problem if its not enabled and set correctly.
hpet only appears on older boards and systems.
as for you haider. your gonna start a fire with that system. buy a cheap 350w psu with a propper 6 pin adapter. or use a dual molex to 6pin adapter. making sure your running off the 12v rail and not the 5 or 3.5.
I had Vista, 7 and 8 running perfectly a big while ago when I didn't have this issue, so it's not a matter of HPET settings (not that I had such an option anyway). There are no explicit voltage settings for the CPU in my BIOS, so there's no undervolting going on as far as I'm aware. Loading the optimised defaults kicks everything back into stock clocks, making it unable to even reach the boot or logon screen without freezing, and sometimes barely passing the POST or... as it used to do some other time before, getting stuck into an infinite reboot loop (with no beeps, just a periodic *click* noise) at which point I was forced to reset the CMOS memory and underclock it again.
Fiddling again with the cables (reseating/pushing them in harder, even though they were apparently plugged in properly) and swapping the two RAM-sticks I have made it actually boot at 3Ghz (RAM still had to stay at 400 DDR2, would otherwise freeze) and run fine until the second I put it under heavy load (Watched 1080p YouTube videos for some 30min, but froze when I merely ran a game for 2-3s). Why does this happen? Why does it apparently get stable if I do that?