Mac OS system password is correct but not in system

Today began to re-study C but the first morning to boot into the system password is clearly correct without words, and later played Apple after the phone to solve the sale.

Today's record how to solve, in case of this problem again, as for the reason why I do not know it is possible to have a connection with the dual system I installed. Just guessing.

1, shut down the system and then restart the system, press option to start, enter recovery mode, select the Common tool, find the Terminate terminal and then enter: ResetPassword

This time will be the interface to let you change the password, you change the password after the restart.

2, after the launch, and many let you enter the password dialog box pop out, you ignore them first. At this point, open the Finder, click to go, this time when you press the option key, there will be a "repository" option appears.

Click Go to "library" to find the folder "Keychains",

Open it and delete all of its files and folders. Then reboot the system.

Mac OS system password is correct but not in system