I'm on WIN10 for about a month or so. Everything is fine, except my hotkey for the brightness was gone (sound still there). Taking a look at the logs showed some programs having trouble (I did not mention this because there were no crashes).
Solution: remove the graphics drivers (via windows) -> restart -> graphics card shows up with "trouble with drivers" -> search for newer drivers -> WIN10 says "already installed" -> everything is fine -> even the hotkeys are working now -> no new entries in the logs -> still don't know what was the reason.
Solution: remove the graphics drivers (via windows) -> restart -> graphics card shows up with "trouble with drivers" -> search for newer drivers -> WIN10 says "already installed" -> everything is fine -> even the hotkeys are working now -> no new entries in the logs -> still don't know what was the reason.