Hm.. Most computers will have a supplied CD that's labeled as "Drivers/Software" bundled with the computer. I know it can be a pain in the arse talking to tech support, but did they suggest where you might be able to find it?
Also, take a look at the HP website. They might have driver package downloads for you.
EDIT: Here we go, here's a list of all the drivers for your computer. HOWEVER, keep in mind that these are Vista drivers. I have no idea if these will be compatible with a copy of XP on that computer.
Also, they don't even mention XP as an OS for this system. It is quite possible that there are no drivers/support for it as an immediate solution from HP.