please help me out this problem?

[DeFender]

I got a core i5 3570 3.4Ghz, 4GB Ram and a Galaxy low power 9800gt 512mb (a second-hand good i bought 2 months ago), the power supply is enough for all components and the OS is windows 7 64bit. I recently encounter freezing system when I play game randomly (everything just frozen but the sound is still ok) and i have to hard reset the pc. I have checked thoroughly all hardware with Burn in Test software and found no problems. I also up to date my graphic driver and lower cpu speed but I still issue the problem. Do you have any idea what kind of thing is that and what is the best solution to rule out this permanently? Thank you in advance.

[Ti]

shrink your C:\ Drive in half of your hard disk size and then use the unallocated space to install Ubuntu Linux 12.04 LTS using the ext4 journaling file system so that you can still play top Games on Linux using STEAM and make your computer run as fast and secure as MAC OS X