Defragmenting your Computer - Why?

Hard drives need love, too. The very nature of how hard drives operate lend themselves to continual maintenance. It is important to perform this maintenance regularly in order to make your computing life much more efficient.

Three key facts about hard drives:

1. Hard disks store data in chunks called sectors. If you imagine the surface of the disk divided into rings (like the rings of a tree), and then imagine dividing each ring into pie-slices, a sector is one pie-slice on one ring. Each sector holds a fixed amount of data, like 512 bytes.
   
2. The hard disk has a small arm that can move from ring to ring on the surface of the disk. To reach a particular sector, the hard disk moves the arm to the right ring and waits for the sector to spin into position.
   
3. Hard disks are slow in computer terms. Compared to the speed of the processor and its memory, the time it takes for the arm to move and for a sector to spin into place is an eon.

Especially because of #3, you want to minimize arm movement and store data in sequential segments on the disk in order for your computer to run efficiently. However, over a period of time, with installing new software, adding new files, deleting files, uninstalling software, and so forth, a lot of the information gets scattered across the hard disk surface. This is called fragmentation and when it occurs, the disk's arm has to move all over the surface and it takes a long time to open the smallest of files. The idea behind the disk defragmenter is to move all the files around so that every file is stored on sequential sectors on sequential rings of the hard disk.

To use Disk Defragmenter, go to the Start Button, click on Programs, then Accessories, then System Tools, and finally Disk Defragmenter. On an XP machine, you should see something very similar to this:

You can click on the Analyze button to see if your hard drive needs defragmenting, or you can just click on the defragment button to get it going right away.

This operation used to take hours in older operating systems, but with Windows XP, the time has been reduced dramatically. Even with a badly defragmented hard drive, it has been my experience that this procedure shouldn't last for more than an hour. You also used to have to worry about the screensaver interrupting your defragment, but not with XP. It would be a good time to go get a cup of coffee, a latte, or a cup of hot chocolate, however. www.howstuffworks.com