No display for log on

Hello,
i have a problem with my log on account in my computer.i have just disable the admiinistator and user account in my computer.well i forget to enable it and it was too late, i have shut down the computer .when i restart the computer ,there is a problem comes.i have no choice given to log on windows, admiinistator and user account was absent.well it is difficult for me, to go to the start menu without log on to this account.please help me ,how i will enable this account in my computer so that i will go to the start menu.