|When BD.NET is installed on 2008 it gives the following accounts/groups full access to the BD.NET installation directory:
1. The default Application Pool Identity. This is the identity given to an application pool when it is first created. If you end up modifying the application pool to use a different identity then you will need to manually give that identity full access to the BD.NET installation directory.
2. The IIS_WPG group. By default this group contains the "LOCAL SYSTEM", "LOCAL SERVICE","NETWORK SERVICE" and IWAM accounts which will cover most cases.
You will also need to make sure the Application Pool Identity has read/write (execute if needed) access to your application.
More information on the Application Pool Identity: