If you are working with a major project, probably you might have numerous numbers of folders and sub-folders, at this kind of particular situation, you can have two options to work with. First thing is to have a Web.config file for each and every folder(s) and Sub-folder(s) and the second one is to have a single Web.config for your entire application. If you use the first approach, then you might be in a smoother way, but what if you have a single Web.config and you need to configure the sub-folder or other folder of your application, the right solution is to use the "Location" tag of "system.web" section of Web.config file. However you can use this tag in either of the discussed methods.