Installing Drupal 7.22 fails at database configuration step on Win7
Thanks Clive for the suggestion.

Writing www/test_pdo.php:

&lt;?php
try{
    $dbh = new pdo( 'mysql:host=127.0.0.1;port=3306;dbname=drupal-7.22',
                    'mydb',
                    'mypassword',
                    array(PDO::ATTR_ERRMODE =&gt; PDO::ERRMODE_EXCEPTION));
    die(json_encode(array('outcome' =&gt; true)));
}
catch(PDOException $ex){
    die(json_encode(array('outcome' =&gt; false, 'message' =&gt; 'Unable to connect')));
}
?&gt;


proved the connection worked for "127.0.0.1" but not for "localhost", my initial setting.

So I changed sites/default/settings.php and reloaded and that worked.