Navigate to the installation folder, then to Data and either delete or rename the following files:
There are two more videos (Black isle logo and game intro), if anyone finds out which files to rename please complete this list. Note that trying to play these disabled movies from the movie selection will crash the game.
If you performed a full install you can play without the CD in your drive by tricking the game. The copy protection will only check for the presence of a CD drive and the presence of a certain file. Set up a virtual CD drive using a tool of your choice and make sure it has one or both of the following files in its file tree:
Wine users can use Wine's winecfg program to set up a folder as a CD drive. Using cracks is not recommended since they can break compatibility with mods.