Cannot verfy access to path

I'm trying to setup FTP on my Windows 2012/IIS 8 server and I'm not having any luck.  

While in IIS I'm under Sites > My FTP Site

I clicked on "Basic Settings" in the right hand nav.   I then click "Test Settings..." under the Edit Site popup window.

Under "Authorization" the Setting message reads "Cannot verify access to path".  

When I click on "Authorization" the Details of the error read as follows:

The server is configured to use pass-through authentication with a built-in account to access the specified physical path. However, IIS Manager cannot verify whether the built-in account has access. Make sure that the application pool identity has Read access to the physical path. If this server is joined to a domain, and the application pool identity is NetworkService or LocalSystem, verify that <domain>\<computer_name>$ has Read access to the physical path. Then test these settings again.

Can someone please walk me through (hand hold) how I correct this problem so I can get FTP up and running?   I'm a app developer not an IIS expert in any way shape or form.

Thanks!