The frequency with which you should defragment your hard drive depends on how often you use it and how much fragmentation your drive has. Generally speaking, if you use your computer every single day and find that your files are opening more slowly than usual, it’s a good idea to defragment your hard drive. Most modern operating systems, such as Windows and Mac OS X, can schedule regular defragmentations for you. Additionally, if you access large media files or have a lot of software installed on your drive, you may need to manually run defragmentation more frequently.