Windows 7: BSOD, happens randomly

Been having a few BSODs since I formatted. Computer just freezes then I seen a screen of a bunch of colorful lines for a second then BSOD.

Windows 7 64bit OEM

About 2 years old system, same with OS.

Run an sfc/scannow command in an elevated command prompt. If errors are found, run it twice more with each scan followed by a reboot.
SFC /SCANNOW Command - System File Checker

Run a chkdsk on the system partition to check for bad sectors or system errors.
Disk Check

Make sure all Windows updates are installed including the latest Service Pack.

The BSOD might also have been caused by defective hardware. Therefore you should:

Test your RAM using Memtest86+. Let it run until 6-8 passes have completed or errors have been found.
RAM - Test with Memtest86+

Test your hardware using Prime95. Watch your machine's temps and stop the test if it starts to overheat. Let it run for up to 2 hours or until errors have been found.
Hardware - Stress Test With Prime95

Test your video card using Furmark. Watch your machine's temps and stop the test if it starts to overheat or artifacts appear on the screen.
Video Card - Stress Test with Furmark