Suddenly my WC4 installation do this... i wonder if i can do something to solve it before re-install it again -_-

EDIT:

FIXED!!!!

http://www.si-gamer.net/gulikoza/bin/WC4DVDFix.zip

:)

That worked perfectly, thank you!
With this fix it was possible to play the German DVD version in combination with the GOG installation of WC4.

Just to be safe, I attached the exe file as an image to this post.
Download, rename "WC4DVDFix.exe.jpg" to "WC4DVDFix.exe" and run it in the installation folder of the game.