When the MySQL server is installed as a service on Windows, it tries to use the service name mysql by default. If a previous installation was not completely removed before installing, this error can be encountered. This occurs because the mysql service already exists on the machine.

Sample

Cannot Create Windows Service for MySQL. Error:0

Resolution

• Choose a different service name when installing.
• On Windows XP or newer, remove the old service with the sc command:
  

  C:\> sc delete mysql
  [SC] DeleteService SUCCESS

• On Windows 2000, download the delsrv.exe tool from http://download.microsoft.com/download/win2000platform/WebPacks/1.00.0.1/NT5/EN-US/delsrv.exe and delete the process with delsrv mysql.

Further Reference

Windows Troubleshooting (MySQL Reference Manual)

MySQL Forums Thread On Error: 0

FAQTs Entry on Error: 0

In MySQL version 4.1, the authentication protocol used for MySQL client-server communications was changed to make it more secure. This changed the format of hashed user passwords and broke compatibility for all clients and APIs designed against MySQL 4.0.

Sample

Warning: mysql_connect(): Client does not support authentication protocol requested by server; consider upgrading MySQL

Resolution

• Upgrade to a 4.1 or higher version of the mysql client.
• Upgrade the API used to one compatible with MySQL 4.1.
  • PHP users can use mysqli or PDO instead of the standard mysql extension. PHP users can also attempt to compile the mysql extension against MySQL 4.1.
  • .NET Users can use Connector/NET instead of Connector/ODBC.
• Run the MySQL server in a mode that uses old password hashing by adding old-passwords to the [mysqld] section of your my.cnf file.
• Update the password of the user who needs to connect from an old-protocol application to use the deprecated password format with this command:
  

  SET PASSWORD FOR ‘user’@'host’ = OLD_PASSWORD(’password’);

Further Reference

Client does not support authentication protocol (MySQL Reference Manual)

Password Hashing as of MySQL 4.1 (MySQL Reference Manual)

mysqli Extension

MySQL APIs (Drivers) for Various Languages