I see the fan assy. and it looks like it has it's own heatsink.This one I'm talking about sits by it's self and is hooked to the motherboard.I'm not really computer literate so I hope you will bear with me.I also understand that dell is the only one who attaches heatsinks this way. Thanks again

FYI: You keep making new threads instead of replying to the original thread.

If it's down near the PCI slots, it's the chipset heatsink. Dell doesn't normally put a fan on that heatsink. If you just need to re-attach the heatsink, get some thermal adhesive and apply it per the instructions.