I have an HP Pavilion desktop PC running Windows XP SP3. When logged in as an administrator, there is no sound, other the windows startup, error, and logoff sounds, and there is no Windows sound icon in the system tray.
When logged in as a limited user, all sound works fine, and the Windows sound icon appears in the system tray.
I created a new admin account and got the same problem. When I changed that account to a limited user, the sound worked fine and the Windows sound icon appeared in the system tray.
All drivers have been re-installed without effect
I would normally have re-installed the operating system by now and start from scratch, but the user can't find his OS disk and license from the manufacturer.