No sound card in Sounds & Audio Devices?

I have a Dell Dimension 4600 running XP Pro SP2. In Device Manager |
Sound, Video and Game Controllers it shows the built-in SoundMAX
Integrated Digital Audio sound card. The properties dialog shows that
the device is working properly.

However, in Control Panel | Sounds and Audio Devices on the Audio tab I
do not see the SoundMAX Integrated Digital Audio device in the playback
device drop-down or in the sound recording device drop-down list.

The only thing in the playback device drop-down list is Microsoft RDP
Audio Driver. The sound recording device drop-down list is empty. I
uninstalled the SoundMAX Integrated Digital Audio device in Device
Manager then restarted Windows. The device was automatically detected
and reinstalled but that did not solve the problem.

How can I get the SoundMAX Integrated Digital Audio device to appear in
the device drop-downs on the Audio tab of the Sounds & Audio Devices
dialog? Thanks.

--
..Bill.