Why is my application is not starting up on Windows?

Sometimes an application will not start up because a previous process from that application is still running in the background and did not properly exit.

To check if the process is still running,
On the Task bar at the bottom of your screen, click on the right button on your mouse. This will bring up a menu. Choose 'Task Manager', then the 'Processes' tab. You can check to see if the processes are there.