Fragmentation makes your hard disk do extra work that can slow down your computer. Removable storage devices such as USB flash drives can also become fragmented. Disk Defragmenter rearranges fragmented data so your disks and drives can work more efficiently. Disk Defragmenter runs on a schedule, but you can also analyze and defragment your disks and drives manually. To do this, follow these steps:
1. Click to open Disk Defragmenter.
2. Under Current status, select the disk you want to defragment.
3. To determine if the disk needs to be defragmented or not, click Analyze disk. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
Once Windows is finished analyzing the disk, you can check the percentage of fragmentation on the disk in the Last Run column. If the number is above 10%, you should defragment the disk.
4. Click Defragment disk. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
Disk Defragmenter might take from several minutes to a few hours to finish, depending on the size and degree of fragmentation of your hard disk. You can still use your computer during the defragmentation process.
• If the disk is already in exclusive use by another program, or if the disk is formatted using a file system other than NTFS file system, FAT, or FAT32, it can't be defragmented.
• Network locations can't be defragmented.
• If a disk that you're expecting to see under Current status is not showing up there, it might be because it contains an error. You should try to repair the disk first, then return to Disk Defragmenter to try again. See
Check your hard disk for errors for more information.