What Is Fragmentation, and What Causes It?

To understand why fragmentation occurs, we must first gain a brief understanding of how a computer stores information. Think of your hard drive as a large grid full of thousands of different blocks. Each one of these blocks has a number assigned to it by your file system (known as an address), for organizational purposes.

When your computer stores information on your hard drive, it requests the required amount of free blocks from your file system, and the file system returns the address to each of these blocks. In an ideal world, these blocks would always be right next to each other, and read at the same time you want to retrieve that file.

Sometimes, however, the file may be stored at several different locations scattered throughout your file system. Therefore, instead of reading a set of blocks in order, it will read a few blocks, then have to look for the next set of blocks, read them, and look for the next set.

The same thing applies to writing files as well. Because your hard drive can only read one block at a time, you can probably understand why this would slow down your disc read and write speeds, thus slowing down your PC. When this happens, it is time for a defrag.

How Often Should You Defrag Your PC?
Fragmentation is a natural occurrence in file systems, and cannot be avoided. As you use your PC, either you or your operating system is constantly moving files around your hard drive. If you leave your computer on all day, every day, you probably will never need to defrag your computer. This is because most operating systems (including Windows) will automatically defrag every couple of weeks in the middle of the night.

If you do not leave your computer on at all times, it is recommended that you defrag your PC every couple weeks under normal use. Heavy users may need to defrag on a weekly basis.

How Can You defrag Your PC?
Fragmentation is a known problem with file systems, and thus every major operating system has a way to defrag your PC without the need of purchasing software. To start a defrag in Windows, follow these simple steps:

Please note that you may need administrative access to the PC you are trying to defragment.