Ok, so finally have all of the permissions set to 777 (including folders within folders for images), configure.php available in both /admin/includes and /includes, and both set to 777. index.php, and all files as far as I can see ok and available on my server.

I have run the installer per above comment, entered DB name/passwords etc, and all seemed ok, got the message:
: Zen Cart™ Setup - Finished
Congratulations!
You have successfully installed Zen Cart™ on your system!

Then...on clicking on either the admin or store front link on this screen (or accessing directly on browser) I am still getting a blank screen. I've looked on the forum, but not sure how to troubleshoot this, as I'm not getting any errors during installation.

Can anyone help? Been at this for 2 days now, and afraid my laptop will shortly be landing in the garden!!!