BSOD While playing any graphic intensive game 0x00000018

Try this. Go to Nvidia's website and download the newest WHQL driver to your desktop Latest NVIDIA ForceWare Video Drivers Windows 7
Then follow this tutorial to install them. It's easy with instructions for each step. NVIDIA Drivers - Avoid Problems Hopefully that will rule out any driver issues.

I would also test the hard drives anyway. New hard drives come damaged frequently.

I think you will see when you go into the display drivers folder, you have a folder of quite a few older drivers, so we want to get rid of them to make sure there are no driver conflicts. Also, Nvidia, for unknown reasons, included a HD Audio sound driver which few people use. And if you have realtek drivers installed, as most boards do, the Nvidia sound driver can cause conflicts with the Realtek drivers. Very few people use the 3D Drivers so why install something that you won't use and which could cause issues with your card. That is the short version of doing a clean install using that method. Also, make sure the 'clean install' box is checked.

As far as your PSU, I don't doubt that it could be causing the problem and I have no idea what the brand is, but as a matter of fact, most every PSU is made in China or Taiwan, just like your motherboard and hard drives and Graphics card and most everything else.

Also, if you would, it would be much easier on us if you filled your system specs in in the user CP or just at the bottom of your last post. Be sure to click save at the bottom of the system spec page. That way it would be there on every post you make and we wouldn't have to read through the whole thread to find them. Also see if you can be a little more specific as to your hardware. I'd like to know the brand and model number of each stick of ram as well as of your PSU. The model number of your motherboard helps if I need to look up information on it. Also, if this is an OEM computer please include the manufacturer and the model number, as well as if it is a desktop or laptop.

Also, could I get you to post screenshots of CPUz the memory tab, mainboard tab and the SPD tab. On the SPD tab it reads each Dimm Slot. You can chose which slot from the dropdown list at the top left of the tab. Just the ones that are populated is all I need.

I know this sounds like a lot, but really is needed. We cant see or hear the computer so we have to depend on you to be our eyes and ears as well as the detail of the hardware we are working with.

You said earlier in the post that you had run memtest86. Did you run memtest86 or Memtest86+. The names are very close but the tests are quite different. Memtest86+ is the much better test and also how many passes did you run with it? It needs 8 passes all at one time. Each pass consists of 9 or 10 tests, each pass and each test tests something different so it takes a minimum of 8 passes to run a complete test. It is best to run it overnight as it will take several hours to complete 8 passes. I know what a pain it is to run all these tests, I've been there myself numerous times. But, they are the only way we have of testing.

The PSU problem is, if you test it with a multimeter or give me the readings from BIOS, that will tell me how much voltage it is putting out at idle. What I don't know is how much voltage is it putting out when under stress, such as gaming.

If you have any questions, please ask. I do not mind explaining anything I ask of you.