hard_disk1.JPG What’s the ideal free space to maintain on your computer’s hard drive? Most experts has recommended that at least 20% free space of the hard drive should be kept free so that this extra space can be used to store temporary files by applications you use, defragmentation programs, or new files/programs that you add in to you computer. You can consider to upgrade your hard drive if the free space in your hard drive has reduced less than 20%.