Disk fragmentation occurs when the operating system is not able to allocate enough contiguous space to store a complete file as a unit, but instead puts parts of it in gaps between other files (usually gaps that exist because they previously held a file that the operating system has since deleted or because the operating system allocated more space than was needed for the file to begin with). With the size of disk drives growing in capacity at an ever increasing rate, the performance loss due to fragmentation increases twice with each doubling of drive capacity. Larger files and greater numbers of files also contribute to fragmentation and consequently performance loss. Defragmentation restores a drive to its original speed by moving the data around within the free space available on the drive, filling in the gaps and reducing or eliminating fragmentation. Disk defragmenting is one of the easiest maintenance procedures that you can perform to keep your system running smoothly and efficiently.