Yeah but would it work in my motherboard? It's a AM2+ and I read on wikipedia that only some AM2+ Motherboards support AM3 processors.....
The specifications listed by HP show it supports AMD Phenom II processors, which are AM3 CPU's. The processors just have to have a TDP of 95 or less.
From what I can tell on the specification sheet, it doesn't state a BIOS update is required. I would review the product download page for your PC ( http://h10025.www1.hp.com/ewfrf/wc/static_software_select?swlinkmsg=100&lc=en&dlc=en&cc=us&docname=c00007682
) and see what is available for BIOS updates. If there are newer BIOS than yours, it will need a BIOS update to the latest BIOS provided for the CPU to work.
Oh and will it work with DDR2 RAM? Sorry If this is the wrong area to post that.
Yes, AM3 processors work with DDR2 and DDR3 processors.