Test your equipment. Cross-check with known-good components one at a time. As I have said earlier in this thread, get another hard disk for a clean install with only Windows and AH (and of course all of the necessary drivers!) to check for a software failure. If the new clean install continues to fail in the same manner as the old one, it's definitely hardware. That's when you should start eliminating the potential culprits one by one, preferably on the clean install. Without any external devices plugged, run Memtest+. If it passes several rounds, your RAM should be OK. If it fails, test your RAM one at a time. If they all pass separately but not together, test them all with another PSU.
Or you may want to start the testing with a known-good PSU to see if the problems persist. If they're gone, you've found the culprit. If not, see the above. Multiple devices randomly failing often indicates a power issue.