Microsoft® Windows® XP Unleashed

Comparing File Systems: FAT, FAT32, and NTFS

Data is scattered all over memory disks, in bits and clusters. An operating system uses a file system to find and organize data. One of the most common file systems used in early Windows versions is the file allocation table (FAT), a table that operating systems use to locate files on a disk. The table resides on the disk, and it contains an entry for each file or directory (folder) on the disk.

The FAT system divides a disk into clusters of bytes (usually from 2048 to 8192 bytes long), and each 16-bit entry in the FAT is used to point to a cluster on the disk. Because the FAT uses only 16 bits, it is not practical for hard drives larger than 128MB. The FAT system is not very good at managing disk ...