Windows 7 Admin Help

[The Legit Shop]

My friend purchased an open-box laptop. The laptop has an administrator account with a password, he can only use the guest account. Is there a way to make himself an admin or delete that account without knowing the password and without reformatting?

 

[Karl]

when restarting, Ctrl+F12. on the screens before it loads, he could re-install it via a recovery partition that way.

 

[The Legit Shop]

already solved. ty