In order to design workflows and interact with Nintex Workflow the product needs to be activated in the site where the functionality is required.
The first step is to activate the product for the Site Collection (see Step 1 below) and the second step is to activate Nintex Workflow per site (see Step 2 below).
To activate Nintex Workflow in a site collection:
It is now possible to activate Nintex Workflow 2010 features in the sites within this site collection.
Nintex Workflow must be activated at the site collection level before it can be activated on the site level.
To activate Nintex Workflow in a site:
It is now possible to start using Nintex Workflow within this site.