Question: I am running my asp.net website through visual studio 2012. 
However when I click run I get this error in the browser: Http 403.14 error(the web server is configured to not list the contents of this directory) !

any suggestions to resolve this error?

Answer: 
I'm sure after years you probably have an answer already. But in case someone else is looking for an answer in the future.

For my problem, I didn't have to at anything to the web.config. I didn't think I would need to either as it was working previously. 

Make sure no folder is named the same as your page, I had a folder called "blog" and a page named "blog.aspx", it was trying to load the folder, I noticed this in the link, changed the folder to blogContent, now it loads fine.
Set default document for your home page or whatever your start page. 

Following link will help you with that <http://www.iis.net/learn/web-hosting/web-server-for-shared-hosting/default-documents>