Unity displays only portion of the screen and is not usable on Windows 10

When I startup Unity on my Windows 10 machine, I see a portion of the screen.
This happens on all dialogs and in the main screen.
Nothing is clickable.
Did a complete reinstall, but the same problem.
See the attached screenshot.

Any ideas whats going on here?
Unity is not usable.

Unity version 2017.3

I have no idea what your issue is, but I recommend dropping to the latest version of 2017.2, because 2017.3 has some serious issues. See if it works then.