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.
http://www.sevenforums.com/tutorials/1538-sfc-scannow-command-system-file-checker.html

Run a chkdsk on the system partition to check for bad sectors or system errors.
http://www.sevenforums.com/tutorials/433-disk-check.html

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.
http://www.sevenforums.com/tutorials/105647-ram-test-memtest86.html

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.
http://www.sevenforums.com/tutorials/100352-hardware-stress-test-prime95.html

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.
http://www.sevenforums.com/tutorials/100356-video-card-stress-test-furmark.html