theashman88 36 Light Poster

I have a Dell Dimension 4500, and I'm trying to take out the motherboard. Its a quick release board and I tried pulling up the tab and removing the system board. No luck.

I went to http://support.dell.com/support/edocs/systems/dim8300/sm/sysboard.htm?dgc=CJ&cid=24471&lid=566643&acd=10550055-3463938- and tried to follow those steps, but no luck. The internals are the same as the 8300 so I tried following those steps.

If anyone has any clues please let me know.