I am still new to this. I am hosted by AQHost and installed Zen Cart using to cpanel on their site. Things start out ok, then I upgraded to 1.3.7 and now I am unable to access any pages to edit. When I go to Tools>definepages editor> (any page) I get the following mesage:

Error: I can not write to this file. Please set the right user permissions on: /home/storename/public_html/includes/languages/english/html_includes/classic/define_main_page.php
Note: you should always edit the files located in your current template override directory, Example: /languages/english/html_includes/
Be sure to make backups after changing your files.

Editing file:
/home/storename/public_html/includes/languages/english/html_includes/classic/define_main_page.php

I have no clue where to find these files. I made sure I had permissions set correctly through cpanel but it did not help.
Any help is appreciated.

I removed the real name and replaced it with 'storename' in info above.

Ray