I have a new MacBook Air that I just restarted and instead of my account login window appearing a grey screen came up with the Apple symbol and a dialogue box for name (not user name) and another for password. It is not accepting my account user name and password. I also tried leaving the boxes blank and hitting return, but that was also wrong. I don't think I set a name and password other than what I used for the account. Can any tell what I am doing wrong? Thanks.