Opening up Inspiron 6000

Right, the first thing you should do is search the Dell site for the manual.  "I've unscrewed every screw": did you make note of where each of these screws came from? The reason is, there are different threads/lengths, and if you put a screw back in the wrong slot it could damage the motherboard/another component, so beware of this.  The best thing is to get a box with different compartments and place each batch of screws in a different compartment. Whatever the state of the laptop now, download the manual and read what it says about how to proceed.

http://support.dell.com/support/edocs/systems/ins6000/en/sm/index.htm