Well the user name should be "admin". I don't know if there is a way to recover a lost password. Having a back door (and telling everyone how to use it) would probably defeat the purpose of having a password to begin with, but you never know. You might just have to reconfigure everything from scratch.
Thanks for your reply. I'd like to know if there is a list of users somewhere, for exemple into the database. I entered the database with PGadmin, can be useful? I'll try all my passwords then, but I'd need to know the username. Thanks