Username or password not working

Hello ... I am trying to adjust the parental control settings in Systems Preferences on my iMac. I am in my account - having used my username and password - but the iMac won't let me unlock the padlock to change parental control because it is saying that I am using the wrong username or password. I am the only person who can access this account ... and I have not changed either the username or the password.
Can anyone help me? Do I need to reinstall the software?
Thankyou in advance.

Hi Jill Welcome to the Forum. Are you trying to set parental controls in your User/Admin account. Much better to add another account and make that one for the children and add parental controls. Add new account and call it kids and just use return instead of a password if they are real young. ONce you are in there then all the controls should become available.


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it looks like your having a issue with your admin password here are 2 articles to do. do them in order that i put them on here.

Mac OS X 10.5 Help: If you forget your administrator password

Resetting your keychain in Mac OS X

do that and you'll have access again.