Go into Control Panel>Users (directly or via Settigns) and make a new user with administrator capabilities. Then login as that user and delete your friends account. Then you start all over.
Remember that it's best to have a spare admin user, just in case your account gets corrupted. So while you're in Control Panel, make 2 new accounts (and login into both to have Windows set them up). Don't forget the password of your spare account!
I just bought this refurbished laptop from a friend but she had aleady entered her name as the user as in C:|user\here name.
How can I change that name?

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