Zune Error

I installed the new Zune Software, but every time I start the software, I get an error....

 

The Zune software is still working, except it does not recognize the Zune (HW v1, new FW 2.1) device (drivers install successfully).

 

I removed and reinstalled everything, but that didn't change anything. On my home computer this works fine.

 

Any ideas?

Done