While trying to install Joomla! 1.5, it's possible to get an error about the database configuration.

As you get to the Database Configuration screen, while the inserted data is correct, there could be an error that says that it can't connect to the database.

The possible problem could be that you've installed MySQL 5 and you're using its password authentication, not supported by Joomla!. You have to revert back to the MySQL 4.1 authentication method.

How can you do that? Open up the MySQL command line, and insert the following SQL line:

SET PASSWORD for 'admin' = OLD_PASSWORD('password');

This way we tell the MySQL server to use the old authentication method, thus allowing the Joomla! 1.5 server to work as expected.