I manged to find a firmware update for my DVD drive. Installed the firmware update successfully, but still I get the same error message 'Please Insert Original DVD "Risen"'

-sometimes it helps to re-insert the dvd and starting the game with the dvd-autostart

I tried this, but I still get the same result, 'Please Insert Original DVD "Risen"'

I downloaded the Tages drivers as suggested by HiddenX. When I ran the setup program 'TagesSetup.exe' It told me the drivers are already installed and asked if I wanted to uninstall them. I answered yes to this and uninstalled the drivers.

Then I ran 'TagesSetup.exe' a second time. The setup program then reported that the drivers are installed and running.

I tried launching Risen again, same result, 'Please Insert Original DVD "Risen"'