This section lists some of the steps you should take when upgrading MySQL on Windows.
Review Upgrading MySQL, for additional information on upgrading MySQL that is not specific to Windows.
You should always back up your current MySQL installation before performing an upgrade. See Database Backup Methods.
Download the latest Windows distribution of MySQL from http://dev.mysql.com/downloads/.
Before upgrading MySQL, you must stop the server. If the server is installed as a service, stop the service with the following command from the command prompt:
C:\> NET STOP MySQL
If you are not running the MySQL server as a service, use the following command to stop it:
C:\> "C:\Program Files\MySQL\MySQL Server 5.1\bin\mysqladmin" -u root shutdown
            If the MySQL root user account has a
            password, you need to invoke mysqladmin
            with the -p option and supply the password
            when prompted.
          
When upgrading to MySQL 5.1 from a version previous to 4.1.5, or when upgrading from a version of MySQL installed from a Zip archive to a version of MySQL installed with the MySQL Installation Wizard, you must manually remove the previous installation and MySQL service (if the server is installed as a service).
To remove the MySQL service, use the following command:
C:\> C:\mysql\bin\mysqld --remove
If you do not remove the existing service, the MySQL Installation Wizard may fail to properly install the new MySQL service.
          When upgrading from MySQL 5.1.23 to MySQL 5.1.24, the change
          in the default location of the data directory from a directory
          within the MySQL installation to the
          AppData folder means that you must
          manually copy the data files from your old installation to the
          new location.
        
If you are using the MySQL Installation Wizard, start the wizard as described in Section 1.3.1, “Using the MySQL Installation Wizard”.
          If you are installing MySQL from a Zip archive, extract the
          archive. You may either overwrite your existing MySQL
          installation (usually located at
          C:\mysql), or install it into a different
          directory, such as C:\mysql5. Overwriting
          the existing installation is recommended.
        
If you were running MySQL as a Windows service and you had to remove the service earlier in this procedure, reinstall the service. (See Section 1.5.6, “Starting MySQL as a Windows Service”.)
Restart the server. For example, use NET START MySQL if you run MySQL as a service, or invoke mysqld directly otherwise.
If you encounter errors, see Section 1.6, “Troubleshooting a MySQL Installation Under Windows”.

