A group of
disk sectors. The
operating system assigns a unique number to each cluster and then keeps track of
files according to which clusters they use. Occasionally, the operating system marks a cluster as being used even though it is not assigned to any file. This is called a
lost cluster. You can free up disk space by reassigning lost clusters, but you should first make sure that the clusters do not, in fact, contain valuable
data. In DOS and Windows, you can find lost clusters with the
ScanDisk utility.
DOS and Windows keep track of clusters with the File Allocation Table (FAT). The size of each cluster depends on the disk's partition size.
Also see clustering.
