I recently got a Macbook and easily set up my user account (admin), plus a standard and guest account.
One day, I opened the computer and the screen was frozen. After waiting a few mins, I forcefully shut it down by holding the power button. When I turned it on, my account was gone, only the standard and guest accounts were left.
I logged in to the standard account. I could see my admin account on the User list. However, no matter what I tried, I could not access it, it just wouldn't show up on the login screen. I ended up changing the standard account to an admin account and deleting my original admin account completely.
A few days later, I tried to create a new admin account with my name. However, when I put my name in, it said that this name was being used by another user, even though I had completely deleted it before.
Any idea how to solve this?