Команда отменяющая команду shutdown -s -t 5400 ( таймер выключения компьютера)

shutdown /a

t ключ времени

Flags
ItemDescription
-dBrings the system down from a distributed mode to a multiuser mode.
-FDoes a fast shutdown, bypassing the messages to other users and bringing the system down as quickly as possible. The +Time [ Message ] options are ignored if the -F flag is specified.
-hHalts the operating system completely; same as the -v flag.
-iSpecifies interactive mode. Displays interactive messages to guide the user through the shutdown.
-kAllows the administrator to broadcast the shutdown warning messages without causing the system to shut down. When the -k flag is used, no other shutdown activity occurs except for sending messages. For example, no processes are killed, no activity is logged in /etc/shutdown.log if the -l flag is specified, and if an /etc/rc.shutdown script exists it does not run.
-lCreates/appends the /etc/shutdown.log file that contains information about the filesystems, daemons, user login, licensing services, network interfaces being brought down. The file may be used for diagnostic and debugging purposes in the event of shutdown failures.
Note: Ensure that there is enough disk space for the shutdown command to log the entries while using this flag.
-mBrings the system down to maintenance (single user) mode.
-pHalts the system without a power down. This is used by uninterruptible power supply (UPS).
Note: The -p flag will have no effect if used in combination with flags not requiring a permanent halt. Power will still be turned off if other operands request a delayed power-on and reboot
-rRestarts the system after being shutdown with the reboot command.
-t mmddHHMM [ yy ]Shuts down the system immediately and then restarts the system on the date specified by mmddHHMM [ yy ] where
mm
Specifies the month.
dd
Specifies the day.
HH
Specifies the hour.
MM
Specifies the minute.
yy
Specifies the year.
The shutdown -t flag cannot be used with the -v or -h option.

Note: This option is only supported on systems that have a power supply which automatically turns power off at shutdown and an alarm to allow reboot at a later time. Systems without this capability may hang or may reboot immediately after shutdown.
-uThis flag is used by diagnostics to update the flash-memory and reboot.
-vHalts the operating system completely.

S нет такого флага