it is a dell Studio XPS 8100. I think they come with an Intel Core i5 now. Also I did bought it pre-owned. I didn't have much money at the time. When I got it, it didn't have any external damage on it. However when I plugged my monitor to the motherboard I didn't get any signal, but there are 2 extension slots that had DVI ports, so I used one of them.
Also the Heatsink or fan wasn't attached to the CPU, so I had to attach it back on. Which leads me to believe that maybe it doesn't have any thermal grease on it (since I didn't notice anything like that on it). It shuts down from time to when I run certain applications on it though, or when its been on for a while. I just tried playing the King Arthur demo and it just shut off literally just 11 minutes ago.
Update: I just ran that Speccy program just to see exactly what my graphics card is (H213H @ 1920x1080 ATI Radeon HD 5700 Series) & it has what I would assume to be the temperature of the CPU hovering around 81-83 degrees Celsius. Pretty messed up I think. :-(