I'm familiar with the Web Site development model but not the Web Application model used by the DNN core and most 3rd party modules.

I downloaded DNN 5.4.2 with source code, unzipped it to my laptop, created an empty database, then opened the VS 2010 solution file. First thing I noticed was the message 'Solution folders are not supported in this version of the application' which occurred because I was using VS 2010 Express. So I installed VS 2010 Professional and tried again. It behaved rather better, but at the end of the build gave the error...

  "http://localhost/DotNetNuke_Community : error  : Unable to open the Web site 'http://localhost/DotNetNuke_Community'.  The Web site 'http://localhost/DotNetNuke_Community' does not exist."

and in the Solution Explorer window I can see DotNetNukeCommunity (unavailable)

What am I missing or what have I done wrong?

Also, I want to look at the source code and trace through execution of the NBStore 3rd party shopping cart module. Is the correct way to set this up to install the module from the zip file and then copy the source code over it? Do I need to delete the NBStore DLLs to get it to execute the code in the source files, or will VS just realise the source code has appeared and start using it?

Thanks!