Hi,
why is the drivers setup not being saved is the question?
I had a similar problem when I installed SP3, I had to uninstal and go back to SP2 and it worked great,
Install SP3 No sound, crazy,
Try going back to SP2 to see if it works, you can reinstall SP3 pack later,
You could clear cmos and try default settings!
If you remove The sound card, Does your onboard sound work?
Have you a resouce conflict in sound card properties with your HD sound on the HD4870?
Will that card wiork in that slot? as I think it may be only x1,
Keep trying m8
Cheers