At the start of a marathon, you’ll see the runners all crowded together. How fast can they run when there’s not much room to run? Not nearly as fast as they would if there was more space between them. The same is true of the data on your hard drive.
If you have less than 25% free hard drive space, you will notice a significant drop in performance.
Free up some disk space by removing old files or temporary folders. A great free program that can help you see which folders have the most stuff in them is called TreeSize Free (for Mac users, try JDiskReport). These handy apps will help you to easily see where most of your disk space is being use.
You’ll want to find files that can be either deleted or copied over to a USB drive or other network location.
Windows users can also try the Disk Cleanup utility included with Windows (Start > Search… > type “Disk Cleanup”).