KB888111 can be installed on top of SP3. Follow the instructions below.
1) Use 7-zip or WinRAR to extract
2) Extract KB888111XPSP2.exe to a folder such as C:\KB888111XPSP2
3) Open Device Manager, search for the Unknown PCI device
4) Right click on the Unknown PCI device to update the driver
5) Point the driver path to this C:\KB888111XPSP2\commonfiles\
It should be able to update. Install the audio driver on your machine. Good luck!
Great advice! Thank you very much! I 'd this error(appr.):"System doesn't need this update" I was going to uninstall SP3 on XP))