I lost the link to the link to the login page as i replaced my PC by a MAC.
second; while i have the password, i don't have the user name.
Could you help

Please read: http://www.zenphoto.org/news/login-and-password-problems

In your case you'll have to drop the Administrator table from the database and re-run setup.
You will then be asked to supply a username and password.

To make changes to the database you'll need a tool like "phpMyAdmin"…or ask your host to do it for you.