Disk Defragmenter is a tool that rearranges fragmented files so your hard disk can work more efficiently. Disk Defragmenter runs on a schedule in this version of Windows, but you can modify the schedule or start it manually.
Open Disk Defragmenter by clicking the Start button, clicking All Programs, clicking Accessories, clicking System Tools, and then clicking Disk Defragmenter. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
Another way to open Disk Defragmenter is to click the Start button. In the Search box, type Disk Defragmenter, and then, in the list of results, double-click Disk Defragmenter.