HTG Explains: Do You Really Need to Defrag Your PC?. Computer files used to get so disorganized on slow, hard drives that Microsoft invented a way to put the files back together in an organized way, to speed up the processing of data on the drives. The old, mechanical hard drives wore out over time, and the defragmentation of the drives became a regular thing. Defragmentation is the way we describe the reorganization of data on the drives, which reduces seek times, and makes the drive faster. However, modern drives; especially Solid State Drives (SSDs), are so fast, and modern OSes are so good at keeping files in their place, that defragging a drive is no longer necessary. If you want to waste a few minutes of your day, go ahead; but, defragging is a bit like organizing the sweaters in your closet by color when it is 90 degrees outside. Just don't, okay?