I get an error message in my browser saying that the connection was reset and the website may be busy when I try to install the forum. So, I tried to first create a database with a username and password: no luck. Then, I tried to insert this new username and password into the config-file: db_settings.php with a similar outcome, but with a slight improvement: there was no longer an error at forum index.php page saying that the default login-user has no permission...

MySQL error message: Access denied for user '[default_login]'@'localhost' (using password: NO)

Instead, this additional error was dropped, so, I guess I'm making some progress?

Then, I deleted these insertions: same response....

Yet, the site can't possibly be busy, 'cuz I can access both the forum's index page and the install index page just fine from my browser.