While most people set up their Macs so all they need is a password, or a finger-press, to authenticate into their machines, the computer your company gives you might be a little more strict. Instead of letting you save your login name or display a list of your system’s users to pick, for example, you might have to actually type in your account name and password.
That’s great for security, but not so great if you’ve forgotten your user name (for whatever reason) on your work Mac, or a MacBook you previously set up and haven’t used in a long time.
If your company lets you, or if you want to make life simpler for your personal Mac, changing over to a login method that only asks you for your password is easy: Go to System Preferences > Users & Groups > Login options, and make sure your login window is set up as “List of users” instead of “Name and password.”
However, this does you little good if you can’t even log into your system to begin with because you’ve forgotten your username. Don’t worry, though. There’s a little trick you can use to figure it out.
Read more at lifehacker.com