Follow these simple steps to add screen shots to your hub.
1. Press F11 to have full screen view
2. Use keyboard to press print screen button which is next to F12
3. Click on start menu and click run..or just use your keyboard and press window button+R (window button could be found between CTRL and ALT key)
4. In the run command type mspaint
5. Paste the screen shot or just use CTRL+V button
6. Choose a filename and save as jpeg, jpg format
7. Add Photo Capsule
8 Select your screenshot from the location where you saved it and you are good to go.
You may check out my Hub as I also use screen shot for Hubs on Microsoft Excel tips and Tricks.
I hope it helps.