I have a website that used to have .dsp file extensions for all pages. There are alot of other sites referencing mine that reference the pages like that, but my pages are all actually .aspx pages. In IIS5, I was able to configure this to work. My problem is I've recently switched from IIS5 to IIS7, and I have no idea how to map these requests (.dsp) to the real file (.aspx) without the server telling me the file doesn't exist.