When you attempt to stop a service but after a while it reports back with an error and either it is stopped and doesn't start anymore, or it is still running and you just can't stop it, then the software of the service crashed and Windows is unable to stop it normally.
What I mean with software part of the service is the following. Like a driver for your computer, a service is just a program that runs on your computer. When a program is installed as a service, it runs invisibly and it can be configured to automatically start when Windows starts. To interact with the service, you have to go to the services tab and you can start/stop the program there, or disable it.
When you choose to stop a service, the service program is interacted with, sending a request to stop it. This allows the service program to stop normally, executing some pre-shutdown commands, and then terminate.
Now, if you attempt to stop the service, but the service is not responding, it is waiting for the service to shutdown. Normally, when a service does not respond, it is automatically stopped by Windows. But there is the rare chance, that the service is running, but for some unknown reason, the shutdown command is queued and its waiting for another task to complete first. If this is the case, the service could have crashed.
If you use software like Process Hacker, you can manually terminate the process that is responsible for the service and refreshing the services list should now list the service as stopped and it can be started normally again.
If you don't want to use additional software, simply reboot the computer, and after a complete reboot, the first thing you want to do is stop that service, though rebooting may fix the issue you are trying to solve in the first place.