Need help with in-game crashing issue + BIOS readings

[PreYeah]

Hi, I have a custom built Cyberpower PC desktop computer built in 2009: It has a Intel i7 920 2.66 GHz, Nvidia GeForce GTX 280, 12 GB GSkill DDR3 RAM, Asus P6T SE Intel X58 Chipset CrossFireX Mainboard, Windows Vista 64-bit, 2 TB HDD running on a 750 Thermaltake Watt power supply.

My computer keeps freezing (audio + video) in-game. This happens when maybe around 20 minutes into the game, and so far, it's crashed on Assassin's Creed Brotherhood, The Sims 3, Arkham City, Space Marines, and Skyrim. But it does fine if I have to use ram-intensive applications like Maya, ZBrush or Photoshop. I have updated Vista and Nvidia drivers, and my graphics card fan is running at a 100%.

I recently installed my RAM sticks and the crashing stopped, but it's been back to the crashing problems ever since I got my power supply replaced.

I never get a BSOD. Instead, the visuals on the screen at the time of the fix gets frozen and the nanosecond of audio playing at the time loops over and over, until I have to reach at the back of the tower and switch it off. When I do start the computer (after waiting a few minutes), sometimes it beeps 4 times (1 long beep, 3 short beeps) which I take that it hasn't found the RAM and I usually shut it down again, until I hear just 1 beep (which is the norm), and it eventually asks me to boot up in Safe Mode or Regular Mode.

I'm wondering if maybe my BIOS hasn't been set right? Right now, the Overclock Tuner (under AI tweaker) is set on Manual, and the RAM is on 1333.

Here are my readings / timings from CPU-Z:

http://imageshack.us/f/23/cpuidmemory.jpg/, http://imageshack.us/f/41/cpuidcpu.jpg/ . And here is my motherboard info: http://imageshack.us/f/849/cpuidmainboard.jpg/ , http://imageshack.us/f/834/cpuidspd.jpg/

My BIOS version is 0403, is this something I'll have to update, and if so, how do I go about it?

Please help me fix this problem. I'm so scared this frequent crashing is going to lead to data corruption Thank you!

[Tradesman]

It might be that the BIOS is wanting CR at 1T, and it's at defualt, check for latest BIOS, reinstall sticks in proper slots, go to BIOS, enable XMP and select profile 1, should be in at 1600, with proper 9-9-9-24 timings then make sure DRAM voltage is correct and CR at 2T. Once you get it stable then could poss try dropping CR to 1 for a performance boost.