Considerations for upgrading MySQL on the Windows platform

Back up old data  
Stop the old server  
Delete the mysql service from the windows system service with the following command:
C:\ >   C:\mysql\bin\mysqld   --remove install mysql as an executable installation file, or extract a directly executable binary package to install  
Re-register for the mysql service with the following command:
C:\ >   C:\mysql\bin\mysqld   --install     restart server  
Other problems can be seen in the various upgrades mentioned above