|Check your internal temperatures either in your BIOS or with Speedfan or a similar program to see if you have an overheating problem.|
If overheating is causing the problem then use a can of compressed air to blow out the vents and remove the build up of dust to allow proper cooling. Post back results.
If not overheating (normal running temperatures) the run Memtest86 through a bootable CD so you can test if the problem is a bad memory card. Run through all tests unless you get any errors, if you get errors, then retest with one stick of memory at a time to identify the bad one. Replace as needed. Replace dual channel memory in pairs. Post back results.
If not memory problems, run hard drive utility from the manufacturer of your actual hard drive (open ports to read the mfg's name) to test the hard drive for bad segments and see if they can be repaired. Post back results.
You have to be a little bit crazy to keep you from going insane.