I have a web application that accesses files in a database folder that sits on a Windows Server 2008 R2 PDC. The PDS has IIS installed and I can configure the app to run fine from that server. I can set the app to find the files via local drive letter or UNC to its own hard drive. To get this to work I added permissions to the IUSR account for the folder with the database files.
I installed a Windows Server 2008 Web Server edition computer on the network. I had this server join the domain by right-clicking My Computer and going to properties, then changing it from workgroup to domain login. I installed the web application we're using to this server and configured it to access the database files on the PDC via the UNC path: \\MAINSERVER\SHARED\DATABASE.
Problem: when I run the application it returns an error that seems to indicate that it doesn't have permissions to the database folder that's on the other server. I went to the authentication item in IIS Manager on this server and verified that the anonymous login uses the IUSR account. I assume this is the same AD account user that the PDC was using when I ran this and it worked.
For testing purposes, I changed the anonymous user ID to use the administrator account and it worked. So my next step was to create a new user in AD called webuser. I added that user to the Administrators group. But even being a member of the administrators group didn't allow this to work.