I am the admin of the computer. My son can't remember a password. I go into his settings and click on show password. It brings up a box with a username that is incorrect. I put in my current password and it responds with username or password is incorrect. The problem is with the username. It can't be changed from the old name to the new name. I had forgotten my password in the past and did a reset to gain access. Please let my know recourse and how to respond to future issues. Windows 10 Chrome 51.0.2
I would simply create a new account and move the contents of the old account over to the newly created account. Since you're the admin, you should have access to go into those directories that are old. When you access it, it might ask you about admin rights, just say yes I'd like to access these.