Hi and Welcome to Just Answer,
Ok, let's take a look at this;
In order to fix this you will need to use your disk or get a disk, and then follow the instructions
Insert the install CD and reboot your computer.
Press the C key while the computer is booting hold it down until the Apple logo appears.Select Reset Password XXXXX the Utilities menu then choose your username. Then follow the rest of the prompts
More info here
If you need more help Let me know
If you find this post helpful please take a few minutes to leave Feedback.
By you leaving Positive Feedback you give your Expert additional opportunities to earn extra CASH and Recognition.
If you would like to give a Bonus they are always welcome.
If there is anything else let me know, If not click accept. Thank You Michael L.