Somewhere on the forum is a post I made some time ago explaining in detail, the procedure to create a CLONE of an existing site, into a SUB-FOLDER on the server.
If you do an advanced search for "clone a zencart site" you may pick it up. Filter by my username - schoolboy.
To show you an example of a CLONED site:
http://www.karenscakes.co.uk
http://www.karenscakes.co.uk/newstore
(I have disabled htpassword for a couple of days, on the newstore site, so take a look).
The purpose for creating this clone was to try a different template and some new modules. By creating a CLONE, I can test my ideas without breaking the functional site.
Bear in mind that BOTH the files AND the database were cloned (duplicated). You do not want to run the CLONE off the live database!
(PS... it can take less than 10 minutes to create a site clone using C-Panel and phpMyAdmin.)