How to Defrag a Computer: Step-by-step Instructions

The word "defrag" is typically used to refer to the Microsoft Windows utility called Disk Defragmenter. It is designed to solve a problem that occurs because of the way hard disks store data.

Initially, what is loaded onto your computer hard drive (in terms of programs, files, and so forth) is encoded onto the hard disk in an orderly fashion. But over time, the drives become far more complexly organized, and fragmented data is stored all over the place.

Here are three key facts about hard disks:

Because of fact No. 3, you want to minimize arm movement as much as possible, and you want data stored in sequential segments on the disk.

So let's imagine that you install a new application onto an empty hard drive. Because the disk is empty, the computer can store the files of the application into sequential sectors on sequential rings. This is an efficient way to place data on a hard disk.

As you use a disk, however, this efficient technique becomes harder for a disk. What happens is that the disk fills up. Then you erase files to reclaim space. These files that you delete are scattered all over the surface of the disk.

When you load a new application or a large file onto the disk, it ends up being stored in hundreds or thousands of these scattered pockets of space. Now when the computer tries to load the scattered pieces, the disk's arm has to move all over the surface and it takes forever.

The idea behind the disk defragmenter is to reorganize the file system so that every file is stored on sequential sectors on sequential rings of the disk. In addition, a good disk defragmenter may also try to optimize things even more, for example by placing all applications "close" to the operating system on the disk to minimize movement when an application loads.

When done well on older disks, defragmenting can significantly increase the speed of file loading. On a new disk that has never filled up or had any significant number of file deletions, it will have almost no effect because everything is stored sequentially already.

As you might imagine, the process of individually picking up and moving thousands of files on a relatively slow hard disk is not a quick process; it normally takes hours.

Ever since the release of the Windows 7 operating system, the disk defragmenter runs automatically. That means that you don't have to do anything, and the defragmentation process will occur periodically. This is certainly convenient, but sometimes, you might want to manually defrag the disk.

If you're experiencing performance issues in Windows, you have a couple of options when it comes to using the disk defragmenter. You can update the schedule on which it runs by doing the following.

If you want to run defrag right away, these are the steps to follow.

If you're using the more recent versions of Windows, you will still have the benefit of a disk defragmenter that will run automatically. However, you can also run a manual defrag on the disk if you want to.

Follow these steps if your PC's performance is lagging, and you think fragmented data might be the culprit.

As you can see, the later versions of Windows don't require you to select disk defragmenter or even click "Defragment Disk" in order to get the process to run. Instead, the "Optimize Drives" option is used as a way to manually defrag the disk.

With the advent of SSD (solid state drive) technology, the need for a defragmentation process has been significantly reduced. Unlike mechanical hard disk drives, SSDs have no moving parts, and the data is stored and modified using chips.

Because of the different, more efficient way that a solid state hard drive operates, the SSDs do not need to be defragmented the way that a hard disk drive does. In fact, defragging can potentially shorten their life span.

Luckily, the operating system on your computer will recognize this, and it won't perform a disk defrag if you have an SSD.