In Defragment, What Does Fragment Mean?

Defragmenting your hard drive is an important step in keeping your computer running smoothly; it keeps your files organized and easily accessible by your hard drive. Without regular defragmentation, you may notice your computer slowing down and files taking longer to access.

1. Information Storage

   • The hard drives of computers using Windows XP, Vista, and 7 are divided into physical clusters of 4 kilobytes each. A cluster is the smallest unit of physical space your hard drive uses. Whenever a file is written to your drive, the drive writes to each cluster in turn, filling up one and then moving to the next.

   File Fragmentation

   • As you move, delete, copy and paste files on your hard drive, the operating system moves the file clusters around to conserve space. When this happens, your files become physically disorganized. For example, when files change in size, small amounts of free space are left on clusters and new files are written to this free space. The hard drive cannot easily read or write to nonconsecutive clusters.

   Effects of File Fragments

   • Multiple file fragments make it difficult for the computer to access the different clusters of the file. This makes the hard drive slower to read and write to files. In extreme circumstances, system files can become fragmented and cause a system crash.

   Dealing with Fragmentation

   • Some tech support desks recommend defragmenting your Windows hard drive at least once per month, more if you frequently edit files. If you don't want to have to remember to defragment, you can set your hard drive to run the utility on a regular schedule. You need at least 15 percent of your drive free at the time of defragmentation to ensure the process goes smoothly. When you defragment your hard drive, the utility searches for fragments of the same file on the drive and moves them to adjacent physical space on the drive.