Random Freezes /similar problem

Hi All,

I have similar problem to the one described in:

https://www.sevenforums.com/crashes-d...reezing-2.html

I even use the same mainboard. My problem is that the applications (games) tend to freeze in random places. The issue occured in a variety of games ranging from GTA IV (can play no longer than an hour - ultra high settings get 60-70FPS) up to Counter Strike, where temperatures do not exceed 45-50C. Games just freeze unexpectadely and a chracteristic sound (something like a stuck CD-AUDIO) can be heard from Loudspeakers. The symptom is the same for all freezes. It does not happen every time. Just in random places and at random times. It's definately more frequent in hardware-demanding games such as GTA4, but also happens in old ones.

PC specification:

GPU: HIS Radeon 5870 Gigabyte 1GB 2xDVI&HDMI&DP (PCI-E)
CPU: AMD Phenom II Quad-Core 965 BOX Black Edition
MB: Asus M4A77TD PRO
RAM: GoodRam DDR3 2X 2GB 1333MHz CL9
PSU: Chieftec (CFT-600-14CS) 600 W
HDD: WD Caviar Black 1TB WD1001FALS 32MB cache SATA-II

*Vista 64bit SP2

As I am not a complete noob when it comes to computeres and electronics I already run a few tests:

OCCT for GPU / CPU/ PSU
HDtune for HDD performance
Memtest86+ & Windiag for RAM

And suprisingly everything is fine. No errors/ no crashes / temperatures acceptable.
DDR3 runs in DUAL CHANNEL mode according to CPU-Z.

Are there any other tests or benchmarks/ results /votlages that you could verify and advice? It's a new machine (bought 2 months ago). Still under warranty - but don't know which item fails. I'd appreciate your help.