You need to fully update Windows, including all optional and recommended updates, prior to installing the latest Crimson 16.10.1 drivers.
thank you very much for your answer! I appreciate that!
Actually, Win7 is totally updated (recommended and optional updates). It is always my first concern, when I install Win7 and the automatic search of updates doesn't work. I install the convenience rollup and a few other packages manually so that Windows can search for updates. Then I install all of it...
I really don't have any idea now. I might try to install Win10, if I find a DVD or .iso from a friend, just to see if the problem is the same...
If you have any idea, or maybe a question I should answer to define the problem a bit better, please feel free!