Plus, it uses up your computer's resources, which slows its processing speed down. Delete (or remove from your desktop) any old files you don't use on a regular basis, or won't ever need again.

Every time you boot your computer, you probably have a few programs you always start up immediately. Here's how to set them to start up automatically whenever you turn on your PC.

Right-click on the white disk icon on your desktop (which will have the same name as the program you just installed), and hit Eject. Then, delete the original .dmg file you downloaded.