Well, that CPU is a Socket A. My CPU is a Socket A as well. The problem is that they don't make them anymore.
You need to find out two things... what FSB your mobo can handle, and what CPUs yo can actually find.
Take your model number and go here:
Click the radio button on "See support and troubleshooting information" and type in you computer's make and model (Pavilion xxxxx). Hit Enter.
Look for a link to your computer's specifications. Click it.
Scroll down until you see info about the CPU. It will tell you what FSB your mobo has. I figure it has 200 FSB, but it might actually go to 266 as well.
Once you have that information, start looking for CPUs with that FSB.
200FSB goes up to 2000+, I think. 266FSB goes up to 2400+. I think.
EDIT: While you are looking at your computer's specs, scroll on down to the RAM portion. Look to see what speed your computer uses (probably PC2100). No need to waste monay on fast RAM when your computer will just downclock it to the speed it needs.
Yeah, that RAM is way too fast for your comp. Here's a good set:
pqi POWER Series 1GB (2 x 512MB) 184-Pin DDR SDRAM Unbuffered DDR 266 (PC 2100)
$73.99 + $4.81 Three Day Shipping