==== shutdown ====
  /? - Display help. This is the same as not typing any options.
  /i -Display the graphical user interface (GUI). This must be the first option.
  /l - Log off. This cannot be used with /m or /d options.
  /s - Shutdown the computer.
  /r - Shutdown and restart the computer.
  /g - Shutdown and restart the computer. After the system is rebooted, restart any registered applications.
  /a - Abort a system shutdown. This can only be used during the time-out period.
  /p - Turn off the local computer with no time-out or warning. Can be used with /d and /f options.
  /h - Hibernate the local computer. Can be used with the /f option.
  /e - Document the reason for an unexpected shutdown of a computer.
  /m - \\computer Specify the target computer.
  /t xxx - Set the time-out period before shutdown to xxx seconds. The valid range is 0-315360000 (10 years), with a default of 30. 
           If the timeout period is   greater than 0, the /f parameter is implied.
  /c - "comment" Comment on the reason for the restart or shutdown. Maximum of 512 characters allowed.
  /f - Force running applications to close without forewarning users. The /f parameter is implied when a value greater than 0 is specified for the /t parameter.
  /d [p|u:]xx:yy - Provide the reason for the restart or shutdown. p indicates that the restart or shutdown is planned. 
                   u indicates that the reason is user defined. If neither p nor u is specified the restart or shutdown is unplanned.