I see. The Pop Up you get when accessing the administrator page is for folder access. It's a security measure, so there's not much I can do about it. Use these on the header to get past it:
Folder/FTP Username and Folder/FTP Password. Both are provided in my first post/opening post (OP).
Once that's done, you'll have to log in properly with the login form on the administrator login page.
Use these ones to log-in:
Site admin account
Username and Password
They're also in the first post fields.
Cheers.