EggXpert

does anyone know what cpu's I might be able to upgrade to if I have a Compaq with a Intel Celeron 430?

You have to look up the model # of your compaq and see what BIOS version it has and what CPUs that Mobo's BIOS supports.

perhaps maybe this one

http://www.newegg.com/Product/Product.aspx?Item=N82E16819116038

But it all depends on the make and model number of your motherboard.

To figure out the make and model number of your board, you can either open up your case and look at the board itself.  Or you can download PC Wizard from www.cpuid.com  this program tells you everything about your computer.  Also,CPU-Z from the same site is another option.

Here is all the info from PC Wizard.

 

 Mainboard :    Asus Lancaster8
Chipset :    Intel i945G/GZ
Processor :    Intel Celeron @ 1800 MHz

It's a custom proprietary motherboard Asus made for Compaq.

(you can't get lancaster8 mobos from asus direct).

Your best bet is to look on the back / bottom of your PC for a compaq sticker, and write down the model # and part #. Look it up on www.hp.com and see what BIOS versions there are for this model PC. Compaq is responsible for supporting these systems.

i945 should be capable of SOME 65nm Core 2 CPU's, but if Compaq never issued a BIOS to support them, then you're stuck with Pentium 4's and Celerons.