Error number 2003 can& #39; t connect to MySQL Server & #39;localhost& #39; (0)

1. Description of the error
   

2. Cause of error
   Recently, I have been able to use the SQLyog to connect to the local database, but in recent days but unable to connect; and always reported the above error, I consulted a lot of information, found that there are a lot of Chinese
   Summarize
   First, the My.ini error in MySQL;
   Second. Insufficient authority.
   Third, the user table may have been modified by MySQL;
   Four, the MySQL service stopped.

3. How to Solve
   For the above reasons, I have also tried to find or report this error;
   Later, I re-installed MySQL, again using SQLyog to connect to the local database, the result is successfully connected.

Error number 2003 can& #39; t connect to MySQL Server & #39;localhost& #39; (0)