XPS M1530 audio driver problem

Hi there!

I hope we can understand each other since I'm not english.

This is my problem:

I downloaded the audio driver for STAC 92XX C-Major HD Audio from the Dell Driver & Downloads site. I tried to install but following error message is interrupting the process:

"ExitError:Error=Device Object non existing. Reboot the system and rerun setup."

I tried that but it doesn't work. This led to following problems:

1) The second headphone output doesn't work anymore

2) When I plug in a microphone into the mic-LineIn, the popup asking me for what I want to use the plugged cable doesn't pop up anymore.

3) The built-in microphone works buggy:

- It doesn't work in the webcam-manager (when I try to record a video)

- At "recording devices" (volume -> right-click) two mics are shown. The second one is marked as standard. When I tip with my finger at the built-in mic, the VU , eh,  rises up to the highest level.

- The mic is working in Skype but it's very, very quiet 

If someone knows help, I'd appreciate!

Cheers!