3D games crashing in Windows 7 64-bit

I have a few questions: I need detailed answer to give you the best support I can give. Stick to details you remember.

1. When the game crashes does the image freeze or does it produce artifacts?
This is artifact GPU effect: http://img337.imageshack.us/img337/2406/bf2142mf9.jpg
2. has it given you a blue screen error? If so can you find the file that crashed it, or the error code.
3. What model is the RAM your using (Speed/latencys or at least a model number).
4. Can you check to see if your GPU is overclocked?

If you need help on how to check for these things:

1. Well just view the screen for the artifacts or the image freezing completely.
2. Blue screens usually tell you the error Code.
3. RAM model or timings/speed can be checked by opening your case/removing your RAM from their slots. This can be done by flipping the 2 switches to the edges if the ram away from the module, this will make the ram pop out. If there are no models, speed or timings on the label; check the ram for labels or any numbers which produce google results.
Speed of ram: DDR2 800 PC6400 or DDR2 1066 PC 8500 or DDR2 667 PC5300 or a number similar to that. I just need the "800" or the "PC6400" part to get the speed.
Latency: Usually measured by 4 numbers, such as 5-5-5-15, 7-7-7-20. The last number should always be significantly higher (2x or higher), also the numbers are almost always separated by a hyphen "-"
4. You can do this using a variety of tools to look for GPU clocks, and memory speed such as: GPUTool by techPowerUp!. Also Nvidia usually gives you a suite with overclocking utilities you can easily check the current GPU Clock, and memory. Once you have the GPU's clock/memory speed you can look up your GPU via Google to compare your current clock/memory speed to the standard of your GPU.
To look up your GPU you need to find out your serial number or model number this can be found on the actual graphics card. Or at least the brand the card says. I doubt it Nvidia branded card (It's still an Nvidia chip but companies stamp their own brand names on the card after applying their own coolers/dvi vga or hdmi connections.).

1. The image simply freezes; it does not produce artifacts.

2. Nope, I've had no blue screen errors at all.

3. I'm afraid I don't have information on the RAM to hand because currently I have not yet opened the PC case up; it is sealed shut with a cable tie which I can remove, but I fear that, if I need to send the machine back to Novatech and they know I have tampered with it, they may not support me anymore. All I know is that it's 2 x 2GB DDR2 RAM at 800 MHz.

4. My GPU is not overclocked. It's running as standard.

Symptoms sound EXACTLY like I experienced when my PSU was wired up wrongly and not giving my GPU enough power.
http://www.tomshardware.co.uk/forum/page-267599_10_0.ht...

What PSU are you running? Is it actually up to the hardware you've got?

My first thought was PSU too, especially given the noise it's making.

@OP have you any way of finding out what PSU you have? make+model+wattage

If you want to find out what RAM you have installed, just check CPUZ under the memory tab.

Thank you for the advice so far guys, it's really helpful. It does sound like the problem Confused Stu is having. Supposing it is the wiring, how hard would it be for me to change this? What should I look for? Is it worth me unsealing the case and doing it myself, or would you recommend that I send it to Novatech to fix? (This would of course take a lot longer and may cost me- to be honest, if it's a simple fix I'd rather do it myself.)

I don't think I have any way of finding out the specs of the PSU- but I am at work at the moment, so I shall certainly check the paper work that came with the machine when I get home. The only thing I know is that it is made by OCZ.

It's actually to do with the GPU not getting enough power, it was just in my case it was down to my wiring because I was crossfiring (2 cards) and had the cables the wrong way round.

I would recommend opening the side of your PC and just looking at the sticker on your PSU and checking the graphics card cables are in properly - that definitely won't void a warranty. Assuming the cables are in, I'd say get the manufacturer to sort it. What's the point of paying something else to make a PC and then not making use of the warranty!  

OCZ is a good PSU company. I am doubtful it is the PSU to be honest, it is not like your running some sort of powerhouse GPU.

Talk to the manufacturer and see if you can pull warranty off them.

Hello, I would appreciate a piece of advice here, and I'm sorry about my English. Recently I bought a rig from a friend, (C2Q, 8GB RAM 1066, 500GB HD, nVidia gtx 260, GigaByte MB) I had a lot of issues and blue screens of death, so I thought it had something to do with the PSU, so I got a new CoolerMaster SilentPro 700W, and no more blue screens, but I'm still having multiple crashes with some games I've installed (Force Unleashed SE, Crysis, Dragon Age, Sims 3). The computer doesn't freeze, it always shows a different dll faulty module at different times (I can play for 10 minutes, and then it crashes, or for 2 hours straight until it happens, but it certainly always happens) In the case of Dragon Age sometimes is MVSCR80.dll or something. In the case of crysis it's the CryAnimation.dll (or something), CryPhysics.dll (o s) and so on. I have all the latest drivers and DirectX. I checked the GPU temperature with Everest shortly after the crashes and it showed 65-70°C (is this ok?) My guess is it has something to do with the OS (Win 7 64 bit), but I'm not sure. I wouldn't like to use a 32 bit based OS, because of the lack of RAM support (up to 4gb), but I'm not sure if Vista (eeew) or XP would give me these troubles on their 64 bit version, or is just a problem with my computer or the software (the games). I do not have problems with old games(silent hill 2), not so demanding games (Torchlight) or emulators. The only thing I can think of now is to change my cheap voltage regulator and get a no-break, because as far as I know, voltage is not so stable in my house, but any help would be very welcomed, I'm going mad with all this crashes thing. Thanks in advance.