Utility software
Defragmentation and storage optimisation
Utility software maintains, protects or improves a computer. On a magnetic hard disk, a file can be split across different areas. Defragmentation rearranges those parts so they are closer together and can be read efficiently. A solid-state drive (SSD) has no moving read head, so seeking between file fragments is not the same delay; repeatedly rewriting data is unnecessary. Windows optimises SSDs with TRIM, rather than traditional defragmentation. This distinction is confirmed in Microsoft's Windows drive guidance (checked November 2026).
Key terms
Compression and encryption utilities
Compression software reduces file size, saving storage space or making a transfer quicker. Lossless compression can restore the original exactly; lossy compression permanently removes some detail, which may be acceptable for a photo or sound file. Encryption software transforms data using a key so it is unreadable without the right key. It can protect files stored on a laptop or sent over a network. Compression saves space; encryption protects confidentiality.
Key terms
Why files become fragmented
On a new hard disk, each file is saved in one piece. Over time, files are deleted, leaving gaps, and other files grow. A new or larger file may be split into fragments to fill the gaps.
To read a fragmented file, the hard disk's read/write head has to move between different places on the disk, which takes time. After defragmentation, each file's parts are stored together and the free space is gathered into one area, so files open faster.
Key terms
Choosing a utility
| Situation | Utility | Why it helps |
|---|---|---|
| A laptop holding confidential reports is often taken out | Encryption | If it is lost, the reports can't be read without the key |
| Some photos are too large to email | Compression | Smaller files are within the size limit and send faster |
| An old hard disk has become slow to open files | Defragmentation | Each file's parts are put back together, so it is read faster |
Exam tip
Say what the utility does and how it helps in the situation given. 'It compresses the file' alone doesn't explain the benefit.