I discovered Checkbox at the time I also discovered that if you press the Windows key on your keyboard, the Unity screen comes up. I had pressed the Windows key and there was Checkbox, an app I had not seen or heard of. It is a very thorough system checker and you can see the impressive list of what it checks on the Ubuntu help page. It checks everything! The video I have on this post has no sound but is a live example of what it is like to use Checkbox and how you can select preferences. I got it to check everything and it takes a while. I did have one problem. There was no opt out when the tests came up and it was too hard at the time to get my headset and earphones when Checkbox was doing the test for those. I was under time pressure . When I used the laptop later in the day I nearly blew my ears off with the racket coming from my speakers. Checkbox had set the volume to very high and the sound distortion was incredible. Easily fixed though, and my own fault for not plugging things in. It’s a very comprehensive diagnostic tool and worth knowing about. Checkbox is still an active Ubuntu project so the refinements and improvements are happening all the time. It is very much a community, collaborative project.