1st update on 22 july 2012 : Fix broken link
CHIPSET
Intel Chipset Installation Utility for ICH8 for Microsoft Windows 2000 and XP:
There are 2 available driver, one form HP and one from INTEL. I believe both driver work just fine but in case one of it did not work, try another one.
Download (HP driver)
Download (Intel Driver)
GRAPHIC:
Mobile Intel 965 Express Chipset Family Video/Graphics Driver
Download
AUDIO :
UAA drivers (Must be installed before installing the audio driver):
Download
Windows XP SP3: Download (KB835221)
Install MS_UAA and Restart!
MS-UAA: (if you laready installed MS-UAA above no need to install again, if you do install it again dun worry about that.
Download (sp33867) size 53MB
Then install
Conextant High Definition audio
Download
If the AUDIO still didn't work read instruction at the end of the post.
MODEM:
(if the modem installed along with the audio no need for this driver)
Conexant HDAUDIO Soft Data Fax Modem with SmartCP Driver
Download
WIRELESS:
There are 3 applicable wireless, choose base on your specs, If you do not know which to choose, try which work for you.
Intel(R) PRO/Wireless 3945ABG Network Driver
Download
Broadcom Wireless Driver
Download
Atheros AR5007 802.11b/g Wireless LAN Driver
Download
LAN/ETHERNET:
Realtek RTL8139/810x Family Fast Ethernet NIC Driver
Download
STORAGE:
Intel Matrix Storage Manager
Download
LIGHTSCRIBE
Lighscribe host system Software
Download
WEBCAM
Cyberlink Youcam Driver
Download
TOUCHPAD
ALPS Touchpad Pointing Device Driver
Download
CARD READER
Ricoh 5 in 1 card reader driver
Download
HP Quickplay
Download
All the driver tested and worked except intel matrix storage manager, webcam and lightscribe. So these 3 driver i added base on the current official driver listed for vista in Hp website. The driver version for XP choose base on the driver that often work with most HP/Compaq model.
_________________________________________________
MANUALLY INSTALL THE AUDIO and MODEM DRIVERS.
To make this guide friendly to end user. I must compose a post with picture so it easy for you to follow step by step guide. This guide also show to install the modem driver. READ THE GUIDE HERE:
http://laptop-driver.blogspot.com/2011/09/compaq-presario-a900-conextant-audio.html
OTHERS:
1. If you want to check if there are still drivers missing refer to my tutorial here:
http://laptop-driver.blogspot.com/2011/01/check-your-driver-in-windows-7.html
(even this guide is for windows 7 you can apply it for XP)
2. If you have others devices with yellow mark. To get the driver for it get me the hardware ID for the devices. to get the hardware id you can refer my guide here.
http://laptop-driver.blogspot.com/2009/12/how-to-check-hardware-id.html
your feedback will help others, so leave your comment below.