As Raze suggested, you can try any of these solutions:
- lowering settings in general (and resolution)
- using the same desktop resolution as you use in the game
- turning off HDR
- Changing the value of UseDesktopResInFullscreen="1" to 1 or 0, depending what it was and trying again. (this value is located in the file "C:\Documents and Settings\%username%\Local Settings\Application Data\Divinity 2\Profile\graphicoptions.xml"
- forcefully changing the resolution in the file mentioned above to the same resolution as your desktop
If these suggestions don't help you, don't hesitate to contact us (firstname.lastname@example.org).