Macintosh HD is not displayed in Finder

Hi guys I just updated my Macbook Pro version 10.6.8 Snow Leopard to OS X El Capitan.

I would say that it was quite a smooth upgrade although it took a while. I think I spent 3-5 hours until the upgrade was finished. This includes the backing up of my time machine, which I also think quite reasonable.

I am now logged on to my new OS X El Capitan and I would say I am quite satisfied.

Just a question, I just noticed that in my Finder I could not find the Macintosh HD anymore.

Could someone please help me how to show this again in my Finder

I attached a screenshot this is now how it looks.

I also noticed that the scroll bar is invisible not unless I have to press the up or down arrow button, then it will appear. How can I have the scrollbar visible.

Any help is appreciated. Thanks and have a nice day