It is after a long absence.
[ it doesn't seem to work with the latest versions of WordPress and Zen Cart. ]
Because I had the inquiry mentioned above, I tested it. The environment that I tested is as follows.

Install URL:http://demo.s-page.net/woz/zen-cart-v1.3.8a/

Zen-Cart >>> zen-cart-v1.3.8a-full-fileset-12112007.zip
Path of Zen-Cart:woz/zen-cart-v1.3.8a

WordPress >>> wordpress-2.5.zip
Path of WordPress:woz/wordpress_25

Tried [a] WordPress and Zen-Cart into separate directories.

Step0)Install of Zen-Cart
Zen-Cart install

Zen-Cart install

Zen-Cart install

Step1)Install of WordPress
Install WordPress

Install WordPress

Install WordPress

Step2)Setting of WordPress
[WordPress admin URL]