Look at your memory. Run memtest 86
. Down the page a bit is a download link for a burnable and bootable iso link. Get this one. It will keep windows from preventing memtest to test the memory it occupies. You will want to run memtest multiple times. Some say 2 or 3 others say up to 13. If you have multiple sticks of ram, test them one at a time on one or 2 passes each. Since none of the software based memory test is foolproof, even if all ram comes back as tested ok, I would run windows one stick at a time for a day, if you have 2 sticks. If you have 4 sticks, pull out one and run windows for a day. Next day, rotate the ram and pull out a different stick and reinsert the first one pulled out.
Another thing that has helped others in the past is to simply rearrange the ram sticks into different slots.
Check other cables within the computer. Sata cables etc.