On my Windows 2012 (not R2) Standard server, I run several VMs. In the process of trying to shut them down, I consistently find an issue where insead of shutting down, the virtual machine get stuck saying "stopping"
In this helpful thread, people say that the problem is actually Routing and Remote Access (RRAS) being on the same server as the VMs. As such, I had luck restarting the RRAS service on the affected server. For me, this worked. I've tried the other suggestions of killing the process - to no avail.