The file system of Windows allocates data blocks comprising a multiple of 512 bytes (1 to 64 KB). Each time a file is created each time a new program is installed, Windows allocates it a number of consecutive blocks. Problem: Over the months, the user deletes some files, uninstall some programs. Windows recovers then blocks on the hard drive and allocated to new files. There is a danger then that these files are spread across remote locations of the disc. Reading the data is slowed down as the head of readings effector many return trips. After a certain time using a computer, it seems to work more slowly.

To remedy this, it is necessary, every three months to carry out a defragmentation of the hard disk. During this operation, reorganized the Windows hard disk so that the blocks that make up a file is located in the wake of each other.

To do this, use the Start / All Programs / System Tools / Disk Defragmenter. Then click Defragment.

Concerned OS: Windows. Mac OS X Panther and Tiger and Leopard can be defragmented with a software specific, but their structure does not make this necessary. The system Linux have journaled file systems, and prevent fragmentation.