Downgraded VISTA to XP PRO. Having Driver Problems for sound and video.

Model of PC ?

HP PAVILLION dv9000 (dv9894ca)

Check this link.
http://forums11.itrc.hp.com/service/forums/bizsupport/questionanswer.do?admit=109447626+1214434879214+28353475&threadId=1242788
remember that if there is a High def audio in that laptop you will need to install the microsoft UAA before the audio drivers.
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01456295&cc=us&lc=en&dlc=en&product=3728197

They didn't work

Can you give us a little more than "they didn't work?" Did you get error messages? What were they? Did the  system fail in some way? How? Have you already tried a number of drivers that have failed? Are the drivers recognized at all? The answers to these questions will help us to help you.

Often, when known good drivers that have worked for others doing a similar downgrade fail, it's because so many drivers have been tried that the computer can no longer recognize the correct ones. In those instances, it is most often required that the downgrade be redone.

Generally, the process I recommend for *ANY* Vista to XP downgrade is this:

Save any important data on the unit to external media such as a USB flash drive, external hard drive, etc.

Download DBAN from:

http://dban.sourceforge.net

Create the necessary media.

Find and download *all* the most current versions of the necessary XP drivers, BIOS, etc.

If the manufacturer has any specs on a proper install order for drivers, find it and print out a copy of that article.

If you haven't already, upgrade the system's BIOS to the most current version BEFORE YOU BEGIN THE DOWNGRADE.

Boot to the media onto which you have burned DBAN. At the prompt, type AUTONUKE. Press Enter. Take a break until you see the black screen that indicates the disk wipe has completed.

Boot to your OS media.

Once the OS has been installed, follow the steps in the Downloading and Installing Drivers in the Correct Order article and install the drivers in that order.

Once you have network connectivity, go to

http://update.microsoft.com

Do a Custom install of the necessary OS updates. This will allow you to see what you'll be getting and opt out of any updates you don't want.

Once this is done, reinstall your software. Update it as necessary.

Finally, copy back your saved data.

My error messages were
For Audio: "Driver installation failed : Could not find the media device for this driver."
For NVIDIA: "The NVIDIA setup program could not locate any drivers that are compatible with your current hardware, Setup will now exit."

Also I redid the downgrade as specified above and am still having problems with just the audio and video.

For the NVIDIA GeForce 8400M GS Video Graphics, try this one:
         
nVIDIA ForceWare X 169.55 for Windows XP/2K 32bit

http://www.laptopvideo2go.com/nvidia/165series/16955.exe

For the audio, does it have the Conexant High-Definition Audio or the  Realtek High-Definition Audio?

the Conexant High-Definition Audio

1. Did the nVidia above work?

2. For the Conexant, did you try the drivers that sparkmaker posted above from:
 http://forums12.itrc.hp.com/service/forums/bizsupport/questionanswer.do?admit=109447627+1214929047510+28353475&threadId=1242788

Specifically, see the post from Cheryl G.  that was posted on Jun 22, 2008 01:29:27 GMT

If the nVidia above didn't work, try this one:

NVIDIA 32bit ForceWare GeForce Go 156.55

http://drivers.softpedia.com/get/GRAPHICS-BOARD/NVIDIA/NVIDIA-32bit-ForceWare-GeForce-Go-15655.shtml

Actual download link here:

http://drivers.softpedia.com/progDownload/NVIDIA-bit-ForceWare-GeForce-Go-Download-40288.html

The audio didnt work at all
The NVIDIA did install however my screen still skips while scrolling up and down pages and when moving things around in windows

Which nVidia did you use? I linked to two different ones.

The Softpedia one.

OK. How did it go with the Conexant?