Editor reverts to old editor URL

Permalink
Hi,
I constructed my new 5.7 website in a sub-folder /fundamental
I've finished and copied the files to public_html and got it so website is fine and works well. However when I log in to edit the site, the login page stays in the public_html folder but where I land after logging into editor mode is back to the /fundamental/site editor I used to originally build the website instead of staying within the public_html folder. I need it not to go back to the back-up /fundamental folder so that the edits effect the live site!
I presume I need to change some code somewhere or somewhere indicate which folder's editor I want to use? I can't see where I need to do this?
Thanks
Roger