Windows XP Service Pack 3
While trying to install Realtek AC97 audio drivers in windows XP SP3 machines showing ”Driver not found” error. Other case we can install the driver without any error but audio will not work .
Microsoft patch is required before any of the HD device drivers are installed, but the patch will only go on windows XP SP2 computers.
Refer the link: http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=888111&kbln=en-us
Open the device manger by typing the command devmgmt.msc. Select sound, Video and game controllers.
If any driver installed uninstall it one by one.
Open the registry editor and browse the following location
Change the CSDVersion value to 200. Restart the computer
Download the Microsoft patch kb888111xpsp2.exe
After updating the patch install the the correct audio drivers for the system.
Restart the computer.
Open the registry editor again.
Locate the HKLM\SYSTEM\CurrentControlSet\Control\Windows path
and change the CSDVersion value to old one i.e 300.