I have upgraded servers and in the process of transferring my application to the new server. The web server runs our web site and an online database. Users can search for specific records and download the data for later analysis. We have two formats, pdf and dat files. The PDF works fine. However, the new site will not open the *.dat file. I can see where the dat file is being created and can go to the folder and open it directly. Also, when I hover the mouse over the button, I see the correct link. However, when I click on the link it takes me to the message "page cannot be displayed." There must be a setting in IIS that allows certain extensions to be open.