Could use some help with this one very perplexing.....

Just recently did a fresh install of Windows XP Pro SP3
completed installation & did all of the Updates etc.
I then go to Dell & download all of the drivers & apps etc. that are part of what the machine came with, & recommended by Dell for this specific PC.

Dell Optiplex GX260
Intel P4 2.66 ghz processor
1GB RAM
160GB Hard drive
DVD-ROM/ CD-RW
Intel Integrated Video Card
Andrea Electronics Integrated Audio Card

I downloaded the entire pool of drivers from Dell support & even installed all of them as the install instructions recommended because they said that it was important the order that the drivers were installed in. So I did all of that rebooting as requested & the sound still did not work It installed a Sound MAX driver. Error I got was #1) Restoring original drivers back to windows, current drivers are missing or corrupted. Please insert Win XP Pro SP3 CD in drive & click Retry. After doing that then I got error #2) Error in re-installing original drivers, please reboot your PC & then reinstall the driver.
So I rebooted & then it came back up I did as the error said & I did a re-install, then got error #3) No ADI Codec installed.

Followed some instruction to remove the specific driver from C:\Windows\Inf\OEMn.inf & also pnf where n in representative of a number corresponding with the OEMn file that is for the Audio driver device & delete both the Inf. & Pnf files for that driver file
then reboot PC & came back up & ran the install again.
Still no sound.
I'm beginning to wonder if the Windows XP Pro CD is the problem but I'm not sure?

Could you please give me some insight with this.