Testing is where you check that everything is working on your computer. It goes hand in hand with troubleshooting.
There are many different things that could cause a problem with your computer. No matter what's causing the issue, troubleshooting will always be a process of trial and error—in some cases, you may need to use several different approaches before you can find a solution
If you're having an issue with your computer, you may be able to find out what's wrong using the process of elimination. This means you'll make a list of things that could be causing the problem and then test them out one by one to eliminate them. Once you've identified the source of your computer issue, it will be easier to find a solution.
This great page gives you lots of tips and tricks of what to check if there is a problem.
Create a new page in your presentation called "Testing and debugging"
Create a table with three columns:
Testing
What happened
How I debugged it
You've already done the testing so just try to remember and write down what worked or didn't work, and how you fixed it.