Test the memory with memtest86+.
Could be power problem.
Check the temperatures with GPU-Z and Realtemp.
Here's a link for Memtest http://www.memtest.org/#downiso
Choose the Pre-Built Bootable ISO (zip)
Once you've downloaded, unzip and burn the ISO file to a blank CD. Boot from the CD when you want to check your memory. As Evongugg pointed out this could be caused by many things, just listen for the sound of your fan, for example, and if you don't hear it, than you computer is definitely going to overheat quickly.