Int 21 Fn 5FC8  - LANtastic V4.0+ - Schedule Server Shutdown               [N]

   AX = 5FC8h
   ES:DI -> ASCIZ server name in form "\\machine"
   DS:SI -> ASCIZ reason string (80 characters)
   CX = number of minutes until shutdown (0 = immediate)
   DX = option flags (see below)

Return: CF clear if successful
   CF set on error
       AX = error code

See Also: AX=5FC9h

Bitfields for option flags:
 bit 0 auto reboot
 bit 1 do not notify users
 bit 2 halt after shutdown
 bit 3 shutdown due to power fail (used by UPS)
 bits 4-7  reserved
 bits 8-14 user definable
 bit 15 reserved