Any idea what this might be? Sometimes I can turn on the computer and it'll run normally for hours, sometimes before I'm even able to boot windows the computer freezes. Most of the time it'll freeze after 30 minutes or so. The screen shows various tints of pink and purple, the cursor doesn't move and the computer becomes completely unresponsive until it restarts itself. I've performed a memory diagnostic and it's not the problem. I'm wondering if it could be the video card, or CPU/motherboard. Any help would be appreciated. I already spent three hours on the phone with an HP customer support guy in India who was no help at all.