May be is not correct one. try to find a tiny button, that will be needed a pin to press with, not your with your fingers. no matter with linex or else. do it again
over 9 years experinced Technicion give this solution to me.
open the DVR casing & find small tyni button on DVR Mother Board. press it, DVR will be reset.
Close Casing and start the DVR and wh en DVR ask admin/password click cancel. now goto menu and set new password/id. reply me when u finished,