No sound after updating windows 7 in bootcamp

Yesterday I succesfully installed windows 7 on my 15 inch retina macbook pro 2.4ghz 8gb ram via bootcamp.
But after 132 windows updates (I think the last one gave an error) and after rebooting it got stuck at "configuring updates".

After all this, windows booted like normal and everything worked fine also the audio.

Until at one point I wanted to turn the volume up and it just went to mute.
When I looked at my audio hardware in device manager, it said that something was wrong with the drivers.
So I removed the installed drivers and reinstalled them (the Cirrus, nvidia HD audio and the realtek driver).
After this, it still says that the drivers are installed incorrectly.

The audio still works perfectly in lion.

Nothing seems to work!

Would someone be so kind to help me?

Thanks in advance!