Auto Logon Please

Hello iam window Nt User i made a change in registry in winlogon set default username and defaultpassword and forceautologon keys then i system logon automatically But main prob is i give default username is a normal user i don’t had any permission to change regedit i didn’t had any privious registry back up.so,

Please tell me what can i do now i want to my system logon as system adm.if u had any personal info mail me at don_knl@yahoo.com.