Could not load file or assembly

I have an issue running NopCommerce 2.3 as an application under an existing website.  I get the following error, "Could not load file or assembly 'ComponentArt.Web.UI' or one of its dependencies. The system cannot find the file specified."

Now I need to remove the module from system.webserver in web.config, however the line "<modules runAllManagedModulesForAllRequests="true" />" is preventing me from doing so.  I get an error if I try to simply add a remove line and another error if I comment the above line out.

Cheers,
Paul