Choose the correct procedure from the drop-down menus to match each description. Shut down and unplug the computer. Remove the CPU case lid. Locate the various fans, and then use compressed air to blow dirt out through the internal slits from inside the case. Save files to an external storage device to aid in file recovery. This process allows you to permanently delete files you no longer need. This mini program may be an unwanted application. Remove programs you accidentally downloaded when you purchased an e-book. This application scans, locates, and makes needed repairs on the hard drive.