Help! I don't remember setting a password on my Mac.

What you see to the left is called a "Dialog Box", and it is one of the possible pop-ups that the OS X system on your Mac may generate. Its purpose is to block malicious and unwanted software access to the core of the operating system. This usually appears when you are installing software or software updates.

For many, this is a cause of alarm and panic because you never set a password on your Mac. Don't worry, you most likely didn't forget the password, but instead just have a blank password. If this is the case, you may simply just hit the return key on your keyboard when this appears, and it will accept your blank password.