In Windows Explorer, browse to the Beyond Divinity folder, switch to details view and check the Type column. Without a divx movie player installed, the config.div file should be listed as a 'DIV File'; with a player installed it could be called something like 'Divx video file'.
Try deleting the files config.div, slashed.cfg and slashed-d3d6.cfg from the Beyond Divinity folder, to force the configuration program to recreate them.
Are you shutting down all non-essential programs (especially anti-virus) before trying to start the game?
