If you just want a single web site and need to change the folder path for that site then edit the basic settings on the site, changing the physical path to the folder of the other site.
If you mean you've already added a completely new web site in IIS then you need to edit the bindings in your sites.
For web, you'll want to edit the http bindings on both the site labeled Default Web Site and your other desired site. Right-click on the site and choose Edit Bindings... or select the site and click on Bindings... in the Actions pane.
The quickest way is to delete the site labeled Default Web Site, but that might not be the desired thing.
The next quickest way is to change the bindings on the Default Web Site to a different port other than 80. Then set the port on your desired site to 80 and leave the Host Name field blank in the http bindings.
If you want to have both sites running and bound to port 80 then in the bindings on the Default Web Site, put something in the Host name box in the http binding. Leave this empty on your desired site. Keep both on port 80 (or change the default web site to another port). This should now make it so that your desired site is used when someone uses
http://localhost or a URL with the hostname of your server.
From your edit - yes, your terminology was a bit off :)
In order to set an app up as the default so that when someone hits the root of your site the app shows up you will have to set up a redirect of some flavor.
Here are a couple of ways to do this:
- Add an HTTP Redirect to the root level of your web site. Click Default Web Site in the navigation tree and then HTTP Redirect. You'll need to decide for yourself how to configure the redirect based on your needs for the app. This could have lingering effects if you decide to undo this in the future depending on what Status code you set.