So I've given up. I can't figure it out. Here's the story. Bought a computer from a friend. It's a custom built PC. 500gb HDD Intel Core 2 Duo 3.0ghZ nVidia 9800GT video card 2GB of RAM (I upgraded to 4GB) The computer randomly freezes, and I don't know why. I don't know much about hardware or where to even begin troubleshooting. I've disconnected all the wires, and reconnected them and made sure everything was in as far as it goes. I've done a fresh install of Windows Vista Home Premium (what it came with), twice. Recommend on where I can start or what I should do please. Getting really irritated that I can't convert videos to play on my phone because it freezes, or play Portal 2 because it freezes.