I have 2 dell computers. One is a dimension 2400. The other is a dimension 4500. I'd like to swap the processors because the 4500 has an AGP slot, but a slower processor. I'm trying to meet the minimum specs for a couple games.

The 2400 is a P4 @ 2.4 GHz. It is a 845GV.
The 4500 is a P4 @ 2.0 GHz. It is a 845E.

If I can swap them, then I assume I'd need to go into the bios and make some changes?

Thanks.
DaveWelcome to the forums Dave.

You should be able to swap the CPUs, but the cooling may not be sufficient.
What games are you wanting to be able to play?Calum,
Thanks for the quick reply. Command and Conquer Red Alert 3. I used www.systemrequirementslab.com to determine the specs.

By more cooling, WOULD I need a bigger CPU fan or case fans? I think I read that the 4500 has a variable speed fan based on temp. I guess I could just monitior the temp to start with? What about bios settings?Although C&C 3 is a strategy game it's fairly demanding on your hardware and especially the CPU, despite the 30fps cap.
You would be able to coax it ALONG on either of those CPUs, provided you have, say, 1GB or more of RAM and a 6800GS or equivalent graphics card, but to turn up the detail and RESOLUTION you'd need something better, preferably a dual core.