Might have a memory problem

[leinad00]

The problem started yesterday, suddenly my computer froze, so I restarted it. Then it crashed and the following message appeared: attempted to execute non-executable memory . My computer started and it seemed to work fine, until today. Now it's crashing again but now it says: CRITICAL_STRUCTURE_CORRUPTION. I googled it and someone said that they've fixed it by installing drivers, which I did. It seemed to work for about 3-4 hours and then it started again. Any idea of what this might be, and how to fix it?
Specs
OS:
Microsoft Windows 8.1 Pro 64-bit
GPU:
AMD Radeon HD 5800 Series (ASUStek Computer Inc)
AMD Radeon HD 5800 Series (XFX Pine Group)
(I am using crossfire)
RAM:
16.0 GB Dual-Channel DDR3 @ 916MHz (9-9-9-24)
CPU:
AMD FX-8150
Motherboard:
ASUSTeK COMPUTER INC. SABERTOOTH 990FX (Socket 942)

EDIT: Also, if I am playing I sometimes hear 3 short beeps. Gave it a search and think it might have something with memory to do.

 

[Darkbreeze]

Run Memtest for 7 full passes on each module individually, not together. Running the test on all the modules at once often creates false test results. Use only one module in the slot designated for single module operation according to the motherboard manual. If all modules pass, it's not a guarantee the modules are good but it reduces the likelihood.

You may also just run single modules for a while to see if the problem happens still or stops with a particular module removed. If it does, try the next module.

http://www.memtest86.com/download.htm

 

[Darkbreeze]

You also make no mention of what speed RAM you are running.

 

[leinad00]

You also make no mention of what speed RAM you are running.

I ran the Memtest for 7 full passes on each stick and it did not detect anything.
The speed of the RAM is 1600

 

[Darkbreeze]

What is your BIOS version?

 

[leinad00]

What is your BIOS version?

BIOS Version/Date American Megatrends Inc. 1604, 16/10/2012

 

[Darkbreeze]

Well, it looks like that is the most recent firmware for that board, but it's pretty old, having been released in 2012. Any hardware released since that date COULD potentially be a problem. Have you recently added ANY new hardware, applications, windows updates, power strips or done anything to make a change that might have created a new issue?

I'd start out by removing all but one module, in the slot designated by the motherboard manual, and running it until it crashes, or doesn't. Repeat the procedure with other modules until the problem either goes away or repeats, which should indicate for you which module has an issue.

You might also simply try to remove and reseat all modules to ensure they are fully seated, have no contaminates on the "teeth" or in the slot.

What is the brand and model number of your power supply, and how old is it?