Your computer's hard disk is like a file cabinet. But while you are working, it can get pretty disorganized. When a program is installed on your computer, the program's files are typically broken up over multiple locations on your hard disk. This is called fragmentation. Fragmentation slows the performance of programs on your computer. Disk Defragmenter reorganizes the files on your hard disk into contiguous blocks, improving the performance of your programs because the files are arranged closer together.

Disk Defragmenter can also create a log file to determine which programs you run most frequently. All such frequently used files are then placed in a single location on your hard disk, which further reduces the time needed to start those programs.

See Defragment your hardrive to keep it in peak condition to learn how.