My iBook went back to factory settings overnight?

[kiragotamac]

Heres the story: my cousin gave me her laptop. I changed the username, passwords, background, settings, name of the harddrive and all that, but left her music and photos on for the time being.
Then I turned it off for the night. I remember something popping off before it turned off, and I think it was just saying changes had been made or something like that. And I THOUGHT I had pressed okay to save those changes....it was late.

But I turn it on this morning and it's practically gone back to basics. EVERYTHING is gone...no music, no photos. The settings and background are factory status. iTunes, iPhoto, and iChat are responding like I'd never used them. The only thing that stayed was my user name, the photo, and the name of the hard drive.

I've looked through the computer and havent found anything.
I couldnt have restored it, could I?
What did I do!?

 

[kiragotamac]

I just found the music, etc. It was under users...and it seems that the computer switched users? The one with everything on it is 'Kira' and has the network symbol. The one that was active when I turned it on has her name and the house symbol. I dont know enough about macs yet to know what this means. I can't make the Kira user go anywhere but the users folder..