Query About Audio.Dll

AudioCtl.dll
AxInterop.TTSObjXLib.dll
Interop.WMPLib.dll

I have found an application where the above Dll’s are used.
But when I try to debug it and it goes to the line where the AudioControl 's instace set to its license, it throws an Exception. And wherever the Dll’s class are used, I find some Exceptions.
But I have been informed that one can run those with the same key in one’s own local machine.

Can anyone put a ray of light on this critical problem.

Thanks