A friend was having very weird problems with his PC. Virus scans would halt on random files. The system would slow down or stop at random intervals. It would occasionally reboot with bizarre BSOD’s (Blue Screens of Death.) I had no idea what the problem could be.
I decided to run the Memtest86 comprehensive, stand-alone memory diagnostic program. After about an hour of running it came across some severe errors. From what I could decipher it looked like a half Mb of RAM was bad. Memtest86 identified the first RAM card as being bad.
I suggested he swap RAM chips just to double check that that was the problem. Turns out that fixed the problem. He now states that the PC is running better than it ever has. And that it was slightly flaky right from brand new.
Note that you need to figure out how to burn an ISO image to your CDR/DVDR drive. And you will need to set up your BIOS or temporary bootup settings to boot from your CDR/DVDR drive.