System restore

Hello,
i use an Asus laptop and tried to do a system restore after my itunes software does not work i try to repair it it just keep given me an error mesage . so i tried system restore only for it to tells me, it has been disabled by group policy ,
i both the laptop to teach myself computer ,so,u see am not really familiar with it ,but would really apreciate it if u can walk me through on how to correct this .