Files and applications on your computer's hard disk drive are not always stored together as one unit, but are often divided into smaller units and scattered around the hard disk. This is caused by normal use.
a fragmented hard disk, a computer has to work harder to gather all of the
small units to perform the commands you give it; this slows down its ability to
access files and run applications. Running Disk Defragmenter helps by putting
all like files and applications into contiguous groups so the computer can
access them quickly.
If you use your computer a lot, it's a good idea to run Disk Defragmenter on a regular basis. It's also a good idea to run Disk Defragmenter after you install a lot of applications to enable them to run at top speed.
Here's how to do it:
1. Click Start, point to Programs, point to Accessories, point to System Tools, and then click Disk Defragmenter.
2. Click the Settings tab, select the check boxes you want (to ensure fastest startup of programs, select the first box), and then click OK.
3. Click the drive you want to defragment, click OK, and then click Yes.
Note: It is best to shut down all your applications before you run Disk Defragmenter.