Answer to: cant get past admin. password.Just bought it at a yard saleIf the password is logon password for Windows OS, you can reset the password with a password reset disk. See: How to Reset Dell Laptop Password? If the password is BIOS password, you need to remove the CMOS battery. See: How to Reset or Remove BIOS Password?
Answer to: Do not know Admin password?4 easy steps to reset your password: See: What to Do When Forget Windows 7 Password?