code:

shutdown /?
Usage: shutdown [/i | /l | /s | /sg | /r | /g | /a | /p | /h | /e | /o] [/hybrid] [/soft] [/fw] [/f]
    [/m \\computer][/t xxx][/d [p|u:]xx:yy [/c "comment"]]

    No args    Display help. This is the same as typing /?.
    /?         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.
    /sg        Shutdown the computer. On the next boot,
               restart any registered applications.
    /r         Full shutdown and restart the computer.
    /g         Full 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.
               Combine with /fw to clear any pending boots to firmware.
    /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.
    /hybrid    Performs a shutdown of the computer and prepares it for fast startup.
               Must be used with /s option.
    /fw        Combine with a shutdown option to cause the next boot to go to the
               firmware user interface.
    /e         Document the reason for an unexpected shutdown of a computer.
    /o         Go to the advanced boot options menu and restart the computer.
               Must be used with /r option.
    /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.