Computer Management & Security Grade 10
Keeping a computer running well and securely requires regular maintenance tasks and an understanding of common threats.
General Housekeeping Tasks
| Task | Purpose |
|---|---|
| Disk Clean-up | Removes temporary files to free up storage space |
| Emptying the Recycle Bin | Permanently deletes files you've already removed, freeing the space they still occupied |
| Uninstalling unused software | Removes programs you no longer use, freeing storage space and reducing clutter |
| Defragmentation | Reorganises fragmented files on HDD for faster access (not needed for SSD) |
| Task Scheduler | Automates tasks like backups and updates at set times |
| File compression | Reduces file size using mathematical algorithms (.zip) |
| Archiving | Moves inactive data to separate storage (long-term, not duplicated) |
| Backup | Creates copies of data on a different device for disaster recovery |
A backup is like keeping a spare key to your house with a trusted neighbour. You hope you never need it, but the day you lock yourself out (a crash, ransomware, a stolen laptop) you will be very glad it exists — and glad it is kept somewhere else, not inside the locked house. That is why the safest backups are stored off-site or in the cloud: a fire or theft that destroys the original should not destroy the copy too.
Types of Backup
| Type | Description |
|---|---|
| Full backup | Complete copy of all files. Slowest but easiest to restore. |
| Incremental backup | Only backs up files changed since last backup (any type). Fast, but restoring needs all increments. |
| Differential backup | Backs up files changed since last full backup. Compromise between full and incremental. |
Backup Locations
- Local — external hard drive kept at same location
- Off-site — physical device kept at a different location
- Cloud/online — e.g. Google Drive, OneDrive — automatic, accessible anywhere
Common Malware Threats
Malware (malicious software) is the umbrella term for any software designed to damage, disrupt or gain unauthorised access to a computer system. It comes in several distinct forms, each with its own way of infecting a device and its own goal.
| Threat | Description | How It Spreads / Example |
|---|---|---|
| Virus | Attaches itself to a file or program and replicates when that file is run, then performs harmful actions | Opening an infected email attachment or running a pirated program |
| Worm | A self-contained program that spreads across a network on its own, without needing the user to open or run anything | Exploits weaknesses in network software to copy itself from one computer to the next |
| Trojan | Disguised as useful, legitimate software, but secretly gives an attacker back-door access to the computer | A "free" game or cracked software download that installs hidden malware alongside it |
| Ransomware | Encrypts the victim's files so they can no longer be opened, then demands payment for the decryption key | WannaCry (2017) locked hospital and business computers worldwide until a ransom was paid |
| Spyware | Secretly runs in the background, tracking browsing habits, keystrokes or personal information without the user's knowledge | Bundled with a free download; sends the collected data back to advertisers or attackers |
| Adware | Automatically displays unwanted advertisements, often as pop-ups, to generate revenue for its creator | Bundled with free software; can also slow the computer down or redirect the browser |
Both replicate and spread, which makes them easy to mix up. The difference is whether a person has to do something: a virus needs a human to open or run the infected file before it can act, while a worm spreads entirely on its own across a network, with no user action required at all.
Security Measures
Each measure below defends against a different kind of risk — some stop malware getting in, some protect data if a device is lost or intercepted, and some protect against problems that have nothing to do with an attacker at all, like a power cut.
| Measure | Purpose | How It Works / Example |
|---|---|---|
| Antivirus | Detects, prevents and removes malware | Scans files against a database of known malware, and watches for suspicious behaviour. Examples: Windows Defender, Avast — should run in the background and update itself automatically. |
| Firewall | Monitors network traffic; blocks unauthorised connections | Sits between the computer and the network, checking every connection against its rules and only letting approved traffic through — e.g. blocking an unknown program from secretly sending your data out to the internet. |
| Strong password | 8+ chars, uppercase, lowercase, numbers, special characters | The more varied and unpredictable a password is, the longer it takes an attacker's software to guess it. Sunset$92Purple! is far stronger than password123, which can be cracked almost instantly. |
| Access rights | Users only access files they are authorised for | Each user account is given a permission level (no access, read-only, or edit) per file or folder — e.g. a learner on the school network can view but not edit the shared timetable, and cannot open staff-only folders at all. |
| UPS | Uninterruptible Power Supply — keeps computer running during power failure | A battery inside the UPS takes over the instant mains power cuts out, giving enough time to save your work and shut down safely instead of losing it. Especially useful in South Africa during load shedding. |
| Encryption | Scrambles data so only authorised parties can read it | A mathematical key scrambles (encrypts) the data; only someone with the matching key can unscramble (decrypt) it. Examples: HTTPS encrypts data between your browser and a website; WhatsApp messages are end-to-end encrypted. |
Both are essential but guard different doors. An antivirus checks files already on the device for known malware. A firewall checks traffic moving into and out of the device over the network, before it ever becomes a file. A well-protected computer needs both.
Organising Files & Folders
A file is a collection of data stored as a single unit (a document, image, song, program). A folder (directory) is a container used to group related files. Organising files means storing them in a logical, meaningful way so they are easy to find later.
Anatomy of a File Path
A path describes exactly where a file lives on a storage device — the drive, the folders, the file name and its extension.
| Part | Example | Meaning |
|---|---|---|
| Drive | C: | The storage device the file is on |
| Path (folders) | \Users\Mari\Documents\IT\ | The chain of folders leading to the file |
| File name | report | The name you gave the file |
| Extension | .docx | Tells the computer what type of file it is |
Put together: C:\Users\Mari\Documents\IT\report.docx
Common File Extensions
The extension (the letters after the dot) tells the operating system which program should open the file.
| Extension | File Type | Example |
|---|---|---|
.txt | Plain text file | notes.txt |
.docx | Microsoft Word document | report.docx |
.xlsx | Microsoft Excel spreadsheet | budget.xlsx |
.pdf | Portable Document Format | manual.pdf |
.jpg / .png | Image files | photo.jpg |
.mp3 / .mp4 | Audio / Video | song.mp3 |
.exe | Executable program | setup.exe |
.accdb | Microsoft Access database | students.accdb |
Why Use a Good File Structure?
- Makes files easier and faster to find
- Reduces duplication — you don't save the same file in many places
- Improves organisation and reduces clutter
- Makes backing up specific folders simpler
A File Manager (e.g. Windows File Explorer) is the software used to view, move, copy, rename and delete files and folders.
Save As vs Export
| Save As | Export | |
|---|---|---|
| Purpose | Save the file under a new name, location, or a different version/format of the same kind | Create a new output file in a different format for use elsewhere |
| Example | Save a .docx as an older Word version | Export a Word document to .pdf |
| Original | Replaced or copied | Stays open and unchanged |
File Naming Best Practices
- Use meaningful file names:
2025_Term1_IT_Project.docx✓,untitled2.docx✗ - Organise files into logical folder structures
- Avoid special characters in file names:
\ / : * ? " < > | - Use underscores or dashes instead of spaces
- Back up regularly — at least weekly