Steps to take to upgrade MySQL in Windows:
1.You should backup your current MySQL installation before proceeding with the upgrade.
2.Download the latest Windows version of MySQL.
3.Before upgrading MySQL, the server must be stopped.
If the server is installed as a service, the service must be stopped at the command prompt with the following command on the command line:
C:>NET STOP MYSQL If the MySQL server is not a service, stop the server with the following command:
C:> C:Program FilesMySQLMySQL Server 5.1binmysqladmin-u root shutdown4.
4.When upgrading from the previous version 4.1.5 to MySQL 5.1, or when upgrading from a Zip file installed MySQL to a MySQL Installation Wizard (installation help) installed MySQL, you must manually uninstall the previously installed MySQL service.
To uninstall the MySQL service, use the following command:
The MySQL Installation Wizard will not install the new MySQL service correctly if you do not want to uninstall the existing service.
5.If you are using the MySQL Installation Wizard (installation help), please refer to the "Using the MySQL Installation Wizard" description to start the help.
6.If you installed MySQL with a Zip file, extract the files.You can overwrite the existing MySQL installation (usually at C:mysql), or install it to another directory, such as C:mysql4.It is recommended to overwrite the original installation.
7.Restart the server.If you run the MySQL service, use NET START MySQL, you can also call mysqld directly.