How to remove a user folder in Windows 7?

I have removed the user account, But there's still a user under Computer> C>Users>willie w. I think this person bought and returned the laptop before I bought it, because the Computer was also named "willie w's Laptop" I can right-click and open anything in the folder, but I can't rename or delete it because the folder or a file in it are always open in another program, though I can't find anything that's actually open. It's driving me crazy. My wife connected her iPhone to the computer, and her phone got renamed willie w's iPhone. I'm waiting for something in the mail saying that willie w. Is my kids' real father.

You might have to restore the computer to original factory settings. This will erase anything that you or willie w put into it.

START type CMD in SEARCH →
Right click the cmd prompt → Run CMD as Administrator.

Type → rd /s /q "c:\users\willie w" [include the quotation marks]