152 Troubleshooting a Microsoft Windows MySQL Server Installation Fatal error: Can’t open and lock privilege tables: Table ’mysql.user’ doesn’t exist [mysqld] # set basedir to your installation path basedir=E:/mysql # set datadir to the location of your data directory datadir=D:/MySQLdata [mysqld] # set basedir to your installation path basedir=C:\\Program Files\\MySQL\\MySQL Server 8.0 # set datadir to the location of your data directory datadir=D:\\MySQLdata These messages often occur when the MySQL base or data directories are installed in different locations than the default locations ( C:\Program Files\MySQL\MySQL Server 8.0  and  C:\Program Files\MySQL\MySQL Server 8.0\data , respectively). This situation can occur when MySQL is upgraded and installed to a new location, but the configuration file is not updated to reflect the new location. In addition, old and new configuration files might conflict. Be sure to delete or rename any old configuration files when upgrading MySQL. If you have installed MySQL to a directory other than  C:\Program Files\MySQL\MySQL Server 8.0 , ensure that the MySQL server is aware of this through the use of a configuration ( my.ini ) file. Put the  my.ini  file in your Windows directory, typically  C:\WINDOWS . To determine its exact location from the value of the  WINDIR  environment variable, issue the following command from the command prompt: You can create or modify an option file with any text editor, such as Notepad. For example, if MySQL is installed in  E:\mysql  and the data directory is  D:\MySQLdata , you can create the option file and set up a  [mysqld]  section to specify values for the  basedir  and  datadir  options: C:\>  echo %WINDIR% Microsoft Windows path names are specified in option files using (forward) slashes rather than backslashes. If you do use backslashes, double them: The rules for use of backslash in option file values are given in Section 4.2.2.2, “Using Option Files” . If you change the  datadir  value in your MySQL configuration file, you must move the contents of the existing MySQL data directory before restarting the MySQL server. See Section 2.3.4.2, “Creating an Option File” . Error: Cannot create Windows service for MySql. Error: 0 This occurs when the Configuration Wizard tries to install the service and finds an existing service with the same name. To permanently remove the old  mysql  service, execute the following command as a user with administrative privileges, on the command line: One solution to this problem is to choose a service name other than  mysql  when using the configuration wizard. This enables the new service to be installed correctly, but leaves the outdated service in place. Although this is harmless, it is best to remove old services that are no longer in use. C:\>  SC DELETE mysql •If you reinstall or upgrade MySQL without first stopping and removing the existing MySQL service and install MySQL using the MySQL Installer, you might see this error: