A hanged service looks like this (as you can see, all Start/Stop/Pause/Resume buttons are disabled):

To kill this service, first note the service name. On the screenshot above, it is ‘EntropySoftCFS’ (ie: the first thing displayed in the “General” tab).
Then, open a DOS shell and run the ‘sc queryex’ command to retrieve the service PID, then use the ‘taskkill’ command to… well, kill it !
C:\>sc queryex EntropySoftCFSSERVICE_NAME: EntropySoftCFSTYPE : 10 WIN32_OWN_PROCESSSTATE : 2 START_PENDING(NOT_STOPPABLE, NOT_PAUSABLE, IGNORES_SHUTDOWN))WIN32_EXIT_CODE : 0 (0x0)SERVICE_EXIT_CODE : 0 (0x0)CHECKPOINT : 0x1WAIT_HINT : 0xbb8PID : 3756FLAGS :C:\>taskkill /PID 3756 /FSUCCESS: The process with PID 3756 has been terminated.
Thanks to The Skiing Cube for this article