When a hard drive on a computer running Windows is formatted, an "allocation unit" size is selected. This is the smallest amount of space that the hard drive can address for a single file. If a file only consumes part of an allocation unit, the remaining portion of the allocation unit cannot be used for another file. These unusable areas of the hard drive are known as "file slack" or "slack space," and the amount of slack space on a hard drive tends to be increased as more files are stored on the hard drive. Calculate the possible amount of file slack on your hard drive to determine how much lost space might be reclaimed if you reduced the number of files on the drive. Writer Bio
