XP, even XP64 does not support native SATA interfaces. There is nothing new going on here and I'd be duplicating the web on how to install and the usual driver hunt.
On top of that you wrote "XP Pro XE64" which came with a hard 127GB drive size limitation. I would be guessing the dv7 drive size but a look finds it's well over that size, a SATA drive and my what a challenge to install XP then recover the Windows 7 system.
Let's hope you know all about recovery of your blown system before you start.
My XP machine died several years back, I bought a new HP dv7-3085dx w/Win7 64bit home premium. I still have programs my business uses that will only run w/XP so I'm wanting to know if there would be any issues I may encounter by installing XP on my 7 machine, assuming it will be partitioned.
I've seen XP Pro XE64 OEM still for sale but before I buy would like to know for sure I won't have any conflicting issues. Also, should I look for the OEM w/service packs or get the SP updates from MS after installing the OS . ?
Thanks for expert advice.