Skype got stuck, and Windows was unable to kill the process even when the UI had disappeared. I had to restart the computer to get Skype again working.
Running as administrator:
C:\Windows\system32>tasklist | find "Skype"
Skype.exe 2708 Console 1 92,328 K
C:\Windows\system32>taskkill.exe /pid 2708 /F /T
SUCCESS: The process with PID 2708 has been terminated.
C:\Windows\system32>tasklist | find "Skype"
Skype.exe 2708 Console 1 92,328 K
How can this be even possible?
Cheers.