using some FTP client (FileZilla is an open source one) connect to your FTP address (ftp.phpnet.us) that you had got just after completing your registration in the phpnet.us site.
You can use your username and password to connect to the FTP once you reach there there is a
www folder open that folder and put the
phpBB folder in it.
After the uploading of files using a browser enter the following kind of address :
http://yourname.phpnet.us/phpBBFolderName/ and it will start the installation in a step by step fashion.
In your case your files are placed outside the www folder.
The
www folder is your web publishing directory so the files placed outside the
www folder won't be accessible via web browser
conclusion
You have to place your phpBB files inside the www folder in your FTP location. I would suggest creating a directory inside
www folder namely phpBB (or something else) and place the phpBB files/pages there and access the install file based on the above furnished syntax.
If you have any more installation problems please let me know
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