If you have your window maximised (taking up the full screen) you may see a bar along the top of your screen.

It can sometimes get in the way of what you are doing. To hide it:

1. Click the ‘Pin’ icon at the left hand side of the toolbar.

Even when hidden a thin grey bar will be visible at the top of the screen.

1. Take your cursor over the grey bar at the top of the screen.
2. Click the ‘Pin’ icon at the left hand side of the toolbar to keep the toolbar on show.