How do I Defragment a Hard Drive?

Taking the time to defragment a hard drive will help to speed up a sluggish computer. Personal computers (PCs) or laptops running on the Microsoft® Windows® operating system come with defragmentation software, but a third-party program might be needed for other operating systems. Software used to defragment a hard drive is easy to run, but it effectively will tie up your computer’s processor and memory, and you should wait to use it at a time when the computer is not needed.

The computer’s operating system will dictate what steps need to be taken to defragment a hard drive. With Windows® systems, you need only to open and start the defragmenter utility. Regularly running this program to defragment a hard drive will help keep your computer running smoothly, especially as the hard drive fills up. Other operating systems do not include similar programs, but third-party software is available for download.

A typical computer hard drive uses a read/write head to store and use information on a disk. When programs and files are first loaded into your computer, the data is written onto the same area of the disk. With use, files commonly are altered or removed, and files begin to spread out over the entire disk. As the disk fills, it becomes more difficult to keep files together, and the computer records information on any free space available.

The computer keeps track of the location of all of this information using a file management system. Older PCs used a system called File Allocation Table (FAT), but this system was replaced by the New Technology File System (NTFS). Fragmentation typically is more problematic for computers that use FAT, and speed is likely to improve dramatically when you defragment a hard drive that uses FAT. NTFS diminishes the effects of fragmentation, and while there also will be benefits, the improvement will be more subtle.

To use a program or open a file, the read/write head needs to collect all relevant information. This is quick and easy when the file exists as a single block, but as the pieces of the file spread out, the read/write head must physically move to each portion of the disk, which slows the process. Collecting the pieces of fragmented files can add to the wear and tear on the computer, eventually leading to costly repairs.

As computer memory grows, fragmentation becomes less detrimental. Fragmentation occurs most often when memory approaches maximum capacity. The addition of memory, through the use of internal or external drives, dramatically increases available memory so that files are less likely to be split apart, and it becomes less necessary to defragment a hard drive. When files or programs are transferred, they will be written to the new disk as a defragmented file.