You didnt mention how you tested your RAM, so I will offer a suggestion. Use memtest. It runs outside the windows environment and can find errors that other tests cannot. You will need to go to their website and download the .iso file. Take that file and use a program like nero, freeisoburner, or imgburn to make a bootable CD. Switch your options in your BIOS so that the CD boots first. The program will run 8 individual tests. When those are finished you will get a message saying the RAM passed. If you get any errors, even one, your RAM is bad and needs to be replaced.memtest download.