MySQL 5.7 Reference Manual
MySQL 5.7 Release Notes
If you installed MySQL using the
package, you may need to initialize the data directory:
Windows distributions prior to MySQL 5.7.7 include a data directory with a set of preinitialized accounts in the
As of 5.7.7, Windows installation operations performed using the
noinstallpackage do not include a data directory. To initialize the data directory, use the instructions at Section 9.1, “Initializing the Data Directory”.