Tryg
When you reinstall all user accounts are removed unless they are in the install profile and even then, it most likely doesn't have the passwords. When you did the install, it should have given you the new admin username and password to use. If you can't find that, you can create a user account from the command line caUtils, look up the command with caUtils help
A new install would not bring any of the data across from your old install either. If you still have the old DB, you can repoint it to that by updating setup.php.
