HD audio & MS UAA won't install on Windows XP SP3 / The way convert windows xp sp3 to sp2

MS UAA is required for Realtek HD audio to work (and I expect on any other HD audio).

The fix is you have to tell your rig it's SP2, then install UAA, then the HD audio will work. 

here's the reg key:

HKLM\SYSTEM\CurrentControlSet\Control\Windows\CSDVersion 

you have to change the dword value

values for XP SP's:

hex 100 = SP1

hex 200 = SP2

hex 300 = SP3

when done you change back to hex 300 and restart

screen shot: