Sounds & Audio Devices

Hello,
I am running windows HP and cannot make the sound work. I have followed the troubleshooter and resintalled the driver C-Media AC97 Audio Device. However in the Sounds and Audio Device Properties box from the control panel, under the volume tab it says....no audio device and under the audio tab it has greyed out the dropdown box for the sound playback default device and in very light grey it says no playback devices. Also on this tab under the sound recording default device it has light greyed out no recording devices and I cannot change this either.

In the Audio tab of the sounds and audio devices box it has a box that says MIDI music playback and the default device says MPU-401 there is nothing else in the drop down box. The use only default devices box is checked with a tick.

Many thanks