Help! My MacBook won't let me log on!!

If you can boot from the install disk there's an option to change your password.
See if that helps.

 

Caps Lock on maybe?

 

Help!

I am having this exact same problem right now, did you ever resolve this issue??

 

if your dad's account is an administrator, try to see if there is some way to restore your account back to the day before it happened, try searching on google or something.

 

Theres no need to re-install.

The problem is your user account not the system.

Does the login window shake when your enter the password?
That means your password is incorrect.
You can log into your dad account and reset the password on your account.

If the login window doesn't shake,something in your account is messed up.

You Dad account is your saving grace.
At that point you log into your dad account and try to fix you user account.
You can make the dad account have full access to your user account folder.

But that might be outside your understanding and you might destroy you account,maybe a apple store visits might be best for you

 

same problem here

Anyone have any suggestions? I'm having the same problem with my Mac (although is quite old & has been acting up as of late so I've been expecting something of the sort) but unfortunately (to the best of my knowledge) my account is the only one (although it was given to me as a graduation present & my uncle installed some programs before he gave it to me so I suppose there is a possibility he had an account but I doubt he'd remember the password 5 years later) Any suggestions would be greatly appreciated!!

 

Have you tried to repair the disk or maybe permissions? Take a look at
http://support.apple.com/kb/HT4718

Good luck!