Will not record full screen (using 2 screens from a docking station)

I have:

1. Windows 10 (lates Version)
2. Docking station
3. 34" screen

When I record - I disconnect the computer and moving into another room to record my video.

But while it seems to record full screen the results are different. Only part of the full screen is recorded.

1. What I have to do is to reboot the pc.
2. I then start up Captivate and it opens up bigger then it should be.
3. So I have to resize it to fit the screen.
4. Then I can record and it turns out like it should.

But this is very consuming. I have to Close all my Windows and tasks to reboot.

Is there another way to make it fit full screen?