As your hard drive becomes fragmented, it slows down your computer!
Whenever you use your computer, your hard drive is busy accessing and creating new files. Over time a single file can get broken up and be scattered throughout your hard drive. Think of it this way: when your hard drive is creating a file, it will start creating it wherever there is room, and when that section fills up, it will go to the next empty space it finds and starts writing again. Eventually, your file system is in a state of chaos and disarray, and every time you want to access a file your computer has to search through your entire hard drive to find all of the bits and pieces of a single file. This is frequently the cause of a slow Windows computer, and of overall computer lag.
Good news! Windows comes with a free defragmentation tool. Simply click on Start-