My computer freezes when playing games. The only games I play are Minecraft and Medieval 2: Total War. Randomly while playing them, the computer will just lock up and require a hard reboot to become responsive again. It is completely random, it could happen right when I turn the game on, or after I have been playing for hours. It usually happens right when I turn it on though. I don't understand why this is happening, system specs follow: OS -- Win 7 32bit Graphics -- EVGA Geforce 250 1024MB PCI Express 2.0 RAM -- OCZ Platinum RAM - 4GB, 2x2GB, 1333MHz, DDR3, low voltage MOBO -- MSI NF750-G55 Motherboard - nForce 750a SLI, ATX, Socket AM3, DDR3, Dual Channel, PCIe, HDMI CPU -- AMD Phenom II X4 955 Black Edition AM3 CPU HDZ955FBGMBOX - 3.20GHz, Socket AM3, 6MB Cache, 2000MHz (4000 MT/s) FSB PSU -- Ultra LS500 Lifetime Series 500W Power Supply - ATX, SATA-Ready, PCI-Express I ran memtest on the RAM, it checked out, my Temperatures are typically below or right at 50 celcius....The answer to this has eluded me for weeks now.