Nothing is displayed by my browser when I try to run phpMyAdmin, what can I do ?

Try to set the $cfg['OBGZip'] directive to FALSE in the phpMyAdmin configuration file. It helps sometimes. Also have a look at your PHP version number: if it contains "4.0b..." it means you're running a beta version of PHP. That's not a so good idea, please upgrade to a plain revision. You can also try a different browser. Additionally you should check your Apache and PHP error logfile and ensure that error reporting is enabled in PHP.