If possible..reboot and see if you have a long string of numbers across the bottom of the screen....a long number like
90000-4567 0009 810e
or anything similar...if it willshow it, that is your "bios string" and it will tell us exactly what motherboard you have...then we can figure out what you can upgrade to.
OR...you might have to take the side of the case off and try to see of you see any writing on the motherboard...although I know those HP cases are small and theres not much room to look around.
I am thinking possibly you have this motherboard
here. Maybe.
See if you see that long number...you either have to write fast or reboot a few times to get it all (or try to hit "pause" to pause the boot..and "enter" to restart the boot)
JP