civicrm4.5.0-wordpress on 1&1 hosting

[Johngm]

I manually installed civicrm in the correct directory via ftp, created a new database and am attempting to activate the civicrm plugin. Although the host is recognised, no matter what user name I enter the form adds the local ip number to the username. When I try to pit the correct ip in or the url extension it still adds the local ip. the database is on a different ip to the files (a 1&1 issue).
I have tried manually editing the default civicrm.settings.php template file but clearly that is not the file the verification procees is looking at as the default settings remain. I have tried editing several files but to no avail.
Can someone tell me what file (and location) the verification process is checking to see if everything is consistent, all file permissions are set correctly.
First time used civicrm/.

[Hershel]

You can not just edit civicrm.settings.php because the installer must create the tables. I presume you are saying that on the CiviCRM Settings page you can't enter the username. Did you ask your host if they can help? It sounds like it may be an issue there.