Stopping a windows service when the stop option is grayed out

You could do it in one line (useful for ci-environments):

taskkill /fi "Services eq SERVICE_NAME" /F

Filter -> Services -> ServiceName equals SERVICE_NAMES -> Force

Source: https://technet.microsoft.com/en-us/library/bb491009.aspx

If you run the command:

sc queryex <service name>

where is the the name of the service, not the display name (spooler, not Print Spooler), at the cmd prompt it will return the PID of the process the service is running as. Take that PID and run

taskkill /F /PID <Service PID>

to force the PID to stop. Sometimes if the process hangs while stopping the GUI won't let you do anything with the service.