AQA 8525 · Section 3.4 · 3.4.3b

Utility
Software

Antivirus · Defragmenter · Backup · Compression · Disk Cleanup

CSZoneAQA GCSE Computer Science 8525

What is Utility Software?

Maintaining and Optimising the System

Utility software is system software that performs maintenance tasks to keep the computer running smoothly and efficiently. It supports the OS without performing productive tasks for users directly.

Often runs in the background automatically

Comes bundled with the OS or can be installed separately (e.g. CCleaner, Malwarebytes)

Types of Utility Software

Key Examples You Must Know

Utility	Purpose
Antivirus	Detects, quarantines, and removes malware and viruses
Defragmenter	Reorganises fragmented HDD files for faster access (not needed for SSDs)
Backup Software	Creates copies of files to protect against data loss
Compression Tool	Reduces file sizes for storage and transmission (e.g. WinZip)
Disk Cleanup	Deletes temporary files, cache, and unnecessary data to free space
Firewall	Monitors and controls incoming/outgoing network traffic

Defragmentation Explained

Why Files Become Fragmented

When files are repeatedly saved and deleted on an HDD, they get stored in non-contiguous sectors. The read head must jump around to access all the parts — slowing performance. Defragmentation reorganises files into contiguous blocks, reducing seek time.

Important:Defragmentation is only needed for HDDs. SSDs have no moving parts — defragging can actually reduce their lifespan.

Exam Practice

Have a go at this question

AQA-style question

Describe the purpose of antivirus software and explain why it needs to be regularly updated.

3 marks

Antivirus software scans files and programs for known malware signatures [1] and quarantines or deletes infected files [1]. It must be regularly updated because new viruses and malware are created constantly — without updates it won't recognise and protect against the latest threats [1].

Key Takeaways

What to Remember

Utility software maintains and optimises the computer system

Key utilities: antivirus, defragmenter, backup, compression, disk cleanup, firewall

Defragmentation helps HDD only — SSDs don't need it

Antivirus must be regularly updated to detect new threats