Defrag

Microsoft utility first included with MS-DOS 6.0 and above and all versions of Windows that is  designed to help chronologically order the data on the hard disk drive. The theory behind defrag is to place each program together instead of scattered throughout the hard disk drive, allowing the read-write head to access the data faster on the hard disk drive. Windows 98 includes an improved version of defrag that is said to place the most commonly accessed data at the beginning of the drive, allowing the read-write head a shorter distance to access the data, making the computer faster. Generally, unless the hard disk drive is seriously fragmented, you will not notice a significant difference after defragging the hard disk drive.

The above image is an example of what Microsoft Windows Defrag may look like, as can be seen this hard disk drive is seriously fragmented (each red portion is fragmented files). In this example if the Defrag was allowed to be completed it's likely the user would notice a significant improvement on performance.

• Additional help and support with Microsoft Defrag can be found on our Defrag help page.
• See our defrag command page for additional information about the MS-DOS and windows command line defrag command.

Also see: Defragmentation, Hard drive definitions, ScanDisk