Mac Restarts with Previous user/owner of computer

[crb1510]

Whenever I reboot my 2011 macbook air I get the login screen for my dads login information. He had previously used the computer and then gave it to me when he got a new one. After I enter the correct password for his login (which is different than my password for my login) it then logins to my desktop and account. However, when I do not completely reboot it, when it just goes to sleep, my login information comes up and i enter my password and then it goes to my desktop like normal.

Is there a way to get rid of my dads old account? I think it may be responsible for why my battery dies so quickly when not charging. Any help would be greatly appreciated. Thank you.

 

[simsaladimbamba]

When logged into your account, go to System Preferences > Accounts / Users & Groups and select the account you want to delete and press the MINUS button on the bottom of the account pane. You may have to unlock the padlock on the bottom before being able to do so.
You have to have admin rights though.

 

[crb1510]

Thats not the issue unfortunately. I have already tried that and there is not another user other than mine (the admin) and guest.