How to restrict download of specified file types in ASP.NET using web.config

In this post i am writing how to restrict your web application so that .txt or any other type files (whatever file extensions you want ) files can not be downloaded. 

Open your web.config file and register following setting in your web.config

<system.web>
   <httpHandlers>
       <add verb="*" path="*.txt" type="System.Web.HttpForbiddenHandler" />
   </httpHandlers>
</system.web>