Crazy Bootup Problem with Laptop

Hi all!

Okay, I've never seen anything like this but my dad called me last night and said his laptop(windows vista) shut down on its own and when he turned it back on his login icons were replaced with one icon with the name Jake and password protected(No idea who this is). This was a previously owned laptop but came just booting straight into windows before i set it up with two accounts, my dad's and guest. I assume it has reverted or reset itself to the previous owners information?? I can't get in touch with him to ask..anyone ever hear of anything like this?

Thanks

Matt