I have a fresh copy of Windows Home Edition, with a bunch of shit installed (Yahoo, AIM, Steam, Limewire, Norton AV Pro) on a Dell Dimension 8200 (don't fucking criticize it, it's good enough for me). I went on Steam and loaded up my favorite level of HL2 (again, don't criticize me, I am my own person). Right when the loading is done, the screen goes black and the computer restarts. This also happens when loading up a Java-based game, which remains anonymous. So, what the hell is wrong with my computer?