Sysprep cannot run on windows 7

Today I want to make a system drive with sysprep function in virtual machine. I get a error message as following:

I don't understand what happen because this tool is built on windows 7 system by default and its operation is very simple --- just click sysprep this execute file.

Next to select the Generalize to create the new SID for new machine.

After this issue happen, I search some articles by Google or  by Microsoft Official Web and find out someone experience. "The wmpnetwk.exe need to be killed on process before run sysprep application."

Really? It confuse me that Windows Media Player Network Sharing Service influence System Preparation. It will be different function on windows system, I think.

Due to I cannot resolve this problem now, it is not dangerous or harmful for me to try it in my thought. When I follow these words to do it, the magic result appear then. The sysprep can be running successfully!

Why? I don't know what's wrong although this problem is resolved. Maybe some DLL file conflict between sysprep and wmpnetwk so that the application is interrupted, I guess.
I don't know whether this method is right operation based on this problem. Maybe it will be proved depend on time or experience in the future!