Utility software

This allows the user to restore the system to a previous state which is saved as a backup. This is only usually used if a system malfunctions.

The storage drive is divided into a number of clusters. The table of contents serves as an address book, keeping a record of each file and the clusters used to store that file. When a file is deleted, the address to the location on the disk is removed.

When files are deleted, unused clusters become available for reuse. These can end up being distributed across a drive, especially if the original files were small. If a large file is then written to a drive, its data could be spread across different clusters leading to file fragmentation. Defragmentation involves rearranging the information on a disk so that files appear in continuous sequences of clusters. This will improve file access times. Most modern operating systems run this process automatically.

Storage drives need to be formatted to be compatible with an OS. The OS usually formats storage media when it is connected to the computer. It is often the case that a storage drive cannot be compatible with both Windows and Mac OS X.

 allow the user to allocate specific users and protects personal files and programs from unauthorised access.

can encrypt data when it is stored, or whenever it is transmitted over a network.

detects and blocks viruses.

can be used to filter between trusted and untrusted networks and prevent programs from communicating through the use of ports.