Using the Task Manager
If your Raspberry Pi doesn’t seem to be responding, it might just be very busy. At the bottom right of the task bar is the CPU Usage Monitor, which tells you how heavily the Raspberry Pi’s processor is being used. It’s a bar chart that scrolls from right to left, so the right-most edge shows the latest information. A green bar that fills the height of the graph indicates that your Raspberry Pi is working flat out, so it might take a moment or two to respond to you, especially when starting programs. In my experience, the Raspberry Pi doesn’t crash often, but it can sometimes be overwhelmed to the extent that it looks like it has. It’s usually worth being patient.
You can see which programs are running on your Raspberry Pi by running the Task Manager (see Figure 4-3). You can find it in the Programs menu among your system tools, but you can also go straight to it by holding down the Ctrl and Alt keys and pressing Delete.
If you have a program that is not responding, you can stop it using the Task Manager. Right-click it in the task list and choose Term to terminate it. This sends a request to the program and gives it a chance to shut down safely, closing any files or other programs it uses. Alternatively, you can choose Kill. That terminates the program immediately, with the possible loss of data.