Just like your car, a computer needs a little bit of maintenance every so often to keep it running smoothly. One task most often overlooked is defragmenting the hard drive. Just what is hard drive defragmenting, and why should you do it?

What Is File Fragmentation?
Think of your computer's hard disk drive as a large filing cabinet for your data. Every folder in the cabinet represents a file, and the papers filling the folder represent the bytes of data that make up the file.

In order to ensure fast access to your papers, you want to keep the folders at the front of the filing cabinet full, so they can be pulled from as quickly as possible. Let's say, however, that when you get a new bunch of paperwork, you completely fill up the folder, have more folders of papers to store, and the folders next to it are full as well. In most filing systems, the extra paperwork is moved to another cabinet and a note left in the original folder as to where the overstock is stored.

Your computer works in much the same way. Space is allocated on the hard drive to keep each file. To keep your computer running smoothly, files are often stored right next to each other in the first available space. However, if you go back and add a few pages to that story you were writing, the computer doesn't see any space on the hard drive to store the new data. Therefore, it moves the new data into the next available spot on the hard drive and leaves itself a "note" of sorts as to where the rest of your file is. This splitting of the file into separate pieces is known as "file fragmentation".

Why should I Defragment My Hard Drive?
As more and more files become more and more fragmented, the longer it takes your computer to access these files, whether you're opening, editing, or even deleting them. If we revisit our filing cabinet analogy, when someone requests the entire stock of a certain folder, the filing employees may have to visit 3-4 different folders to fill the order. This same exact thing is happening on your hard drive.

What Does Defragmenting My Hard Drive Do?
The disk defragmentation process takes all the pieces of a file and puts them back together in one single spot on the hard drive. Additionally, your file is moved toward the front of the drive so that it can be accessed faster.

How Often Do I Need to Defragment My Hard Drive?
This depends on how you use your computer. If you access a lot of large files on a frequent basis, chances are your files will fragment more quickly than someone who only checks his e-mail a couple of times a week. Generally speaking, the average home user should defragment his or her hard drive 4-6 times per year (which is every 2-3 months).