HP Pavilion DV9718CA Windows XP Driver

Make your Vista Recovery cd/dvd,then you can delete both partitions if desired.Or just format C: with XP installer.IF warranty service is ever needed,HP sometimes requires Vista be reinstalled.
Here

Chipset Driver:
nForce 630a - Windows XP/2000
install and reboot.If offered,
choose the option to install ONLY the drivers:
Download

Nvidia Graphics:
NVIDIA 32bit ForceWare GeForce Go 156.55
Download

Modem:
Download

Net Framework:
Download

HP Quick Launch:
Download

Audio:

Install UAA first:
Download

After that:
Download
and install audio, if you have problems with audio remove this driver and install driver below:

Download and follow steps below

Unzip to a folder.Run installer.if it errors use Device Manager.
From Device Manager,right click "Audio Device on HD",choose Update driver,

No to connect,

Install from a list or specific location,

Don't search I will choose the driver to install,

For the Hardware Type select 'Show All Devices'

Remove the check from "Show Compatible Hardware" and click on "Have Disk".

Next...browse to the unzipped folder and choose the "WiSVHe5.inf".

Ignore XP when it complains.
Reboot.
Drivers from DV9000z cto series should work for missing drivers.

For audio, you need MS UAA,with a reboot before Conexant Audio and Modem drivers.HP Quick Launch,Broadcom Wireless(?),Ricoh Media Card Reader,AMD Update,HP Wireless Assistant are all here.
(Do not use a bios,chipset or graphics)
Download

Your model may have Broadcom or Atheros Wireless adapter,check before wiping Vista out.

Atheros AR5007 drivers:
Download