Beginner’s Reference Manual
A complete guide from powering on your first computer to creating documents, spreadsheets, navigating the internet, and staying safe online — with confidence.
What computers are, what they do, and why they matter in everyday life.
A computer is a general-purpose, programmable device capable of calculating, storing, and processing information at great speed. Computers are used across virtually every area of modern life — from typing a letter at home to running global banking systems.
At their core, computers work with binary code — a system of only two values: 0 and 1 (off and on). Every letter you type, every image you see on screen, and every calculation performed is ultimately stored and processed as a sequence of these binary digits.
Computers are tools. Like any tool, their value depends on how well the person using them understands them. This manual will give you that understanding step by step.
All information in a computer is converted to binary code for processing, then converted back into a form humans can read — letters, numbers, pictures, or sound. The main memory that holds information while you work is called RAM (Random Access Memory). For permanent storage, data is saved to a hard drive or external device.
The physical parts of a computer — the components you can touch and see.
Hardware refers to all the physical components of a computer system. These are organized into four categories: input devices, output devices, processing components, and storage devices.
The rectangular box (or compact case) that houses the CPU, RAM, hard drive, and other core components is called the system unit or tower. All other devices — monitor, keyboard, mouse, and printer — connect to it through cables or wirelessly.
RAM is temporary. If the computer loses power before you save, your work is lost. Always save your files regularly to the hard drive.
Press the power button once and wait for Windows to fully load. You may be asked to log in with a username and password.
Never turn the computer off at the wall socket while it is running. This can corrupt your operating system and cause data loss.
The programs and instructions that tell hardware what to do.
Software is the set of instructions that tells hardware how to work. Unlike hardware, you cannot touch software — it exists as data stored on the computer. There are two main categories:
The most widely used operating system in the world. Windows provides a graphical user interface (GUI) — a visual environment where you interact using icons, windows, and menus rather than typing commands. Windows also enables multi-tasking — running several programs at the same time.
| Version | Released | Notes |
|---|---|---|
| Windows XP | 2001 | Widely used in training centres and schools for many years |
| Windows 7 | 2009 | Highly regarded for stability; many offices still use it |
| Windows 10 | 2015 | Current standard; consistent updates and broad support |
| Windows 11 | 2021 | Latest version; redesigned Start menu and interface |
Always log out when you leave a shared computer. Leaving your session open allows others to access your files and accounts.
Understanding the visual environment of Windows and how to work with open applications.
After logging in, you arrive at the Desktop — the main working area of Windows. Think of it as a real desk: a surface on which you place and open things.
Every open window has three control buttons in its top-right corner:
| Button | Symbol | What It Does |
|---|---|---|
| Minimize | — | Hides the window but keeps the program running. Find it again in the Taskbar. |
| Maximize | □ | Expands the window to fill the entire screen. |
| Restore Down | ❐ | Reduces a maximized window back to its previous size. |
| Close | ✕ | Closes the window and ends the program. |
Click any program's button in the Taskbar to switch to it. You can also hold Alt and press Tab repeatedly to cycle through all open windows.
When you delete a file, it moves to the Recycle Bin rather than disappearing immediately — this is your safety net.
Once you empty the Recycle Bin, files cannot be easily recovered. Only empty it when you are certain you no longer need those files.
Mastering the two most important input devices gives you control over everything else.
| Action | How To | What It Does |
|---|---|---|
| Click | Press and release the left button once | Selects an item (file, icon, or option) |
| Double-click | Press the left button twice quickly | Opens a file or program |
| Right-click | Press the right button once | Opens a context menu with extra options |
| Click-and-drag | Hold left button and move the mouse | Moves an item from one place to another |
| Scroll wheel | Roll the wheel forward or backward | Scrolls up or down through a page |
| Key | Function |
|---|---|
| Enter ↵ | Confirms an action; starts a new line in text |
| Backspace ⌫ | Deletes the character to the left of the cursor |
| Delete Del | Deletes the character to the right of the cursor |
| Shift ⇧ | Held down to type capital letters or upper symbols (e.g., Shift+5 = %) |
| Caps Lock | Toggle: when on (light lit), all letters type in CAPITALS |
| Space Bar | Inserts a blank space between words |
| Tab ↹ | Moves cursor to next tab stop; also moves between form fields |
| Escape Esc | Cancels the current action or closes a menu |
| Arrow Keys ↑↓←→ | Move the cursor one character or line in any direction |
| F1 | Opens Help in most Windows programs |
Organizing your work so you can always find what you need.
A file is a collection of data stored under a single name — a document, a photo, a spreadsheet. A folder is a container that holds files and other folders to keep things organized. Think of folders like labeled drawers in a filing cabinet.
Name your files clearly from the start. "Report_Sales_March2024.docx" is far easier to find later than "Document1.docx".
Press Win + E to open File Explorer instantly, or right-click the Start button and choose Open Windows Explorer.
| Folder Name | What Goes Inside |
|---|---|
| Documents | Letters, reports, forms, text documents |
| Spreadsheets | Excel files, budgets, records |
| Photos | Images and pictures |
| Downloads | Files downloaded from the internet |
| Work / School | Subject-specific subfolders for assignments or projects |
Connecting to the world's largest library and communicating electronically.
The Internet is a vast global network of computers connected together, allowing the sharing of information. It contains more information than any library in the world. The World Wide Web (WWW) is a portion of the internet consisting of billions of linked webpages containing text, images, video, and audio.
A web browser is the program you use to access and view webpages. Common browsers include:
Every webpage has a unique address called a URL (Uniform Resource Locator). Type it into the address bar at the top of the browser and press Enter.
| URL Part | Example | Meaning |
|---|---|---|
| Protocol | https:// | Secure connection (padlock icon visible) |
| Domain | www.google.com | The website's name and address |
| Extension | .com / .org / .gov | Indicates the type of site |
| Path | /search?q=computers | The specific page within the site |
Copying someone else's words and presenting them as your own is plagiarism. Always rewrite information in your own words, and acknowledge your sources.
Email (electronic mail) lets you send messages, files, and images to anyone with an email address anywhere in the world, instantly and for free.
| Field | Purpose |
|---|---|
| To: | The recipient's email address |
| Subject: | A brief title describing what the email is about |
| CC: | Carbon Copy — send a copy to additional recipients |
| BCC: | Blind Carbon Copy — others receive it without seeing who else did |
| Body | The main message you are writing |
| Attachment 📎 | A file (document, photo) sent along with the message |
| Folder | What It Contains |
|---|---|
| Inbox | All incoming emails you have received |
| Sent | Copies of emails you have sent |
| Drafts | Emails you started but did not yet send |
| Spam / Junk | Unwanted or suspicious emails filtered automatically |
| Trash | Deleted emails, cleared periodically |
The world's most widely used word processor — for letters, reports, and documents of every kind.
Microsoft Word uses a Ribbon interface — a strip of tabs at the top of the screen, each containing related tools grouped together.
Before formatting text, you must first select it. Selected text appears highlighted in blue.
| What to Select | How |
|---|---|
| Any amount of text | Click at the start, hold and drag to the end |
| A single word | Double-click the word |
| A whole sentence | Ctrl + click anywhere in the sentence |
| A full line | Click once in the left white margin beside that line |
| A full paragraph | Double-click in the left margin beside the paragraph |
| The entire document | Ctrl + A |
| Formatting | Shortcut | What It Does |
|---|---|---|
| Bold | Ctrl+B | Makes text thicker and darker |
| Italic | Ctrl+I | Makes text slant to the right |
| Underline | Ctrl+U | Draws a line under text |
| Strikethrough | Ribbon button | Draws a line through text |
| Superscript | Ribbon button | Raises text: 10² |
| Subscript | Ribbon button | Lowers text: H₂O |
| Change case | Aa dropdown | Switches between UPPERCASE, lowercase, Sentence case |
| Font colour | A with bar | Changes the colour of selected text |
| Highlight | Highlighter icon | Adds background colour behind text |
| Alignment | Shortcut | Description |
|---|---|---|
| Left (default) | Ctrl+L | Text lines up against the left margin. Ragged right edge. |
| Centre | Ctrl+E | Text is centered between both margins. Used for headings. |
| Right | Ctrl+R | Text lines up against the right margin. Used for dates. |
| Justify | Ctrl+J | Text fills both margins evenly. Common in formal documents. |
Press Ctrl+S every few minutes. If the computer loses power, you will only lose changes since the last save.
Word automatically underlines suspected errors as you type — red for spelling, green for grammar. To correct:
A powerful tool for organizing numbers, performing calculations, and creating charts.
Never type anything other than numbers and decimal points into a cell intended for calculations. If you type a letter accidentally, Excel treats the whole cell as text and will not include it in formulas.
Formulas always begin with an equals sign =. This tells Excel you want it to calculate, not just display text.
| Operation | Symbol | Example Formula | Result |
|---|---|---|---|
| Addition | + | =A1+B1 | Adds the values in A1 and B1 |
| Subtraction | - | =A1-B1 | Subtracts B1 from A1 |
| Multiplication | * | =A1*B1 | Multiplies A1 by B1 |
| Division | / | =A1/B1 | Divides A1 by B1 |
| Function | Example | What It Does |
|---|---|---|
| SUM | =SUM(A1:A10) | Adds up all values from A1 to A10 |
| AVERAGE | =AVERAGE(B1:B5) | Calculates the mean of values B1 to B5 |
| MAX | =MAX(C1:C20) | Returns the highest value in the range |
| MIN | =MIN(C1:C20) | Returns the lowest value in the range |
| COUNT | =COUNT(D1:D15) | Counts how many cells contain numbers |
A colon (:) means "from...to". So A1:A10 means "all cells from A1 to A10".
| Format | Example Display | When to Use |
|---|---|---|
| General | 4000 | Default — plain number |
| Currency | ₦4,000.00 | Money values with symbol and decimals |
| Percentage | 95% | Proportion values (0.95 displays as 95%) |
| Comma | 4,000.00 | Large numbers with thousand separators |
| Date | 28/08/2024 | Calendar dates in consistent format |
The AutoFill handle is a small black square at the bottom-right corner of a selected cell. Drag it to copy patterns and formulas quickly across many cells.
Below are three real-world practice datasets drawn from Nigerian daily life. Open a blank Excel workbook and try building each one yourself.
| A — Product | B — Units | C — Unit Price (₦) | D — Total Value (₦) | |
|---|---|---|---|---|
| 1 | iPhone 15 Charger | 40 | 3,500 | =B2*C2 → 140,000 |
| 2 | Tecno Spark 20 Cover | 60 | 1,200 | =B3*C3 → 72,000 |
| 3 | Samsung USB Cable | 85 | 850 | =B4*C4 → 72,250 |
| 4 | Bluetooth Earpiece | 25 | 5,500 | =B5*C5 → 137,500 |
| 5 | Power Bank (10,000mAh) | 18 | 12,000 | =B6*C6 → 216,000 |
| 6 | Screen Protector | 120 | 500 | =B7*C7 → 60,000 |
| TOTAL | =SUM(B2:B7) | =AVERAGE(C2:C7) | =SUM(D2:D7) → ₦697,750 |
=B2*C2 (multiply), =SUM(D2:D7) (total value), =AVERAGE(C2:C7) (average price = ₦3,925). Format column C and D as Currency (₦) in the Home tab.| A — Category | B — Budget (₦) | C — Actual (₦) | D — Difference (₦) | |
|---|---|---|---|---|
| 1 | Generator Fuel | 45,000 | 52,000 | =B2-C2 → −7,000 |
| 2 | Choir Robes (dry cleaning) | 12,000 | 10,500 | =B3-C3 → 1,500 |
| 3 | Printing (bulletins) | 8,000 | 8,000 | =B4-C4 → 0 |
| 4 | Welfare / Benevolence | 20,000 | 15,000 | =B5-C5 → 5,000 |
| 5 | Sound System Maintenance | 30,000 | 34,500 | =B6-C6 → −4,500 |
| TOTAL | =SUM(B2:B6) → ₦115,000 | =SUM(C2:C6) → ₦120,000 | =SUM(D2:D6) → −₦5,000 |
| A — Student Name | B — Fees Due (₦) | C — Amount Paid (₦) | D — Balance (₦) | |
|---|---|---|---|---|
| 1 | Adaeze Okonkwo | 45,000 | 45,000 | =C2-B2 → 0 |
| 2 | Emeka Nwosu | 45,000 | 20,000 | =C3-B3 → −25,000 |
| 3 | Fatima Al-Hassan | 45,000 | 45,000 | =C4-B4 → 0 |
| 4 | Taiwo Adeyemi | 45,000 | 30,000 | =C5-B5 → −15,000 |
| 5 | Ngozi Eze | 45,000 | 45,000 | =C6-B6 → 0 |
| TOTAL / % | =SUM(B2:B6) → ₦225,000 | =SUM(C2:C6) → ₦185,000 | =SUM(C2:C6)/SUM(B2:B6) → 82% |
=SUM(C2:C6)/SUM(B2:B6) gives a decimal — format that cell as Percentage in the Home tab and it displays as 82%. Negative balances (still owing) show in red if you apply Conditional Formatting.Below are three real-world practice datasets. Open a blank Excel workbook and try building each one yourself.
| A — Product | B — Units | C — Unit Price ($) | D — Total Value ($) | |
|---|---|---|---|---|
| 1 | USB-C Cable | 50 | 4.99 | =B2*C2 → 249.50 |
| 2 | Phone Case | 30 | 8.50 | =B3*C3 → 255.00 |
| 3 | Bluetooth Speaker | 12 | 29.99 | =B4*C4 → 359.88 |
| 4 | Screen Protector | 80 | 2.99 | =B5*C5 → 239.20 |
| 5 | Power Bank | 15 | 24.99 | =B6*C6 → 374.85 |
| TOTAL | =SUM(B2:B6) | =AVERAGE(C2:C6) | =SUM(D2:D6) → $1,478.43 |
=B2*C2 (multiply), =SUM(D2:D6) (total value), =AVERAGE(C2:C6) (average price = $14.29). Format columns C and D as Currency ($) in the Home tab.| A — Category | B — Budget ($) | C — Actual ($) | D — Difference ($) | |
|---|---|---|---|---|
| 1 | Rent | 800 | 800 | =B2-C2 → 0 |
| 2 | Groceries | 300 | 342 | =B3-C3 → −42 |
| 3 | Transport | 150 | 120 | =B4-C4 → 30 |
| 4 | Utilities | 120 | 135 | =B5-C5 → −15 |
| 5 | Entertainment | 100 | 60 | =B6-C6 → 40 |
| TOTAL | =SUM(B2:B6) → $1,470 | =SUM(C2:C6) → $1,457 | =SUM(D2:D6) → $13 saved |
| A — Student | B — Maths | C — English | D — Science | E — Average | |
|---|---|---|---|---|---|
| 1 | Alice Tan | 78 | 85 | 70 | =AVERAGE(B2:D2) → 77.7 |
| 2 | John Smith | 55 | 60 | 48 | =AVERAGE(B3:D3) → 54.3 |
| 3 | Maria Garcia | 92 | 88 | 95 | =AVERAGE(B4:D4) → 91.7 |
| Class Avg | =AVERAGE(B2:B4) | =AVERAGE(C2:C4) | =AVERAGE(D2:D4) | =AVERAGE(E2:E4) → 74.6 |
=AVERAGE(B2:D2) adds all three scores and divides by 3 automatically. Use =MAX(E2:E4) to find the top student's average, and =MIN(E2:E4) for the lowest.| Chart Type | Best For |
|---|---|
| Column / Bar | Comparing quantities across categories (e.g., monthly sales) |
| Line | Showing trends over time (e.g., temperature over a year) |
| Pie | Showing proportions of a whole (e.g., market share %) |
| Area | Showing cumulative totals over time |
| Term | Definition |
|---|---|
| Binary code | The language computers use, consisting only of 0s and 1s |
| CPU | Central Processing Unit — the brain of the computer |
| RAM | Random Access Memory — temporary working memory; lost when power is cut |
| Hard Drive | Permanent storage device; keeps data even when switched off |
| Operating System | Master software managing all hardware (e.g. Windows) |
| GUI | Graphical User Interface — visual environment using icons and windows |
| Icon | A small picture on screen representing a file, folder, or program |
| Desktop | The main working area of Windows, visible after logging in |
| Taskbar | Bar at bottom of screen showing open programs and the Start button |
| URL | Uniform Resource Locator — a webpage address (e.g. www.google.com) |
| Browser | Program for viewing webpages (Chrome, Edge, Firefox) |
| Search Engine | Website that finds information across the web (e.g. Google) |
| Cursor | The blinking line showing where your next typed character will appear |
| Pointer | The arrow on screen controlled by the mouse |
| Hyperlink | Clickable text or image that takes you to another webpage or location |
| Ribbon | The toolbar in Microsoft Office showing tabs and grouped tools |
| Cell Reference | A cell's address in Excel, e.g. B4 (column B, row 4) |
| Formula | An instruction in Excel beginning with = that performs a calculation |
| AutoFill | Excel feature that extends patterns across cells using the fill handle |
| Multi-tasking | Running more than one program at the same time |
| Recycle Bin | Temporary holding area for deleted files before permanent removal |
Staying safe, spotting misinformation, and protecting yourself on social media and messaging platforms.
Social media are digital platforms that allow people to create, share, and respond to content — text, photos, videos, and voice messages. In Nigeria, the most widely used platforms include WhatsApp, Facebook, Instagram, TikTok, and X (formerly Twitter). Each platform has different features, audiences, and risks.
WhatsApp is Nigeria's most widely used messaging platform. Many Nigerians receive their news, health information, and advice through WhatsApp groups. This makes it both a powerful tool and a common source of misinformation.
Every time you create an account, post a photo, or send a message, you leave a trace of information online. Protecting that information is a basic digital skill.
| Platform | Where to Find Settings | What to Set |
|---|---|---|
| Settings → Privacy | Last Seen, Profile Photo, About — set to "My Contacts" or "Nobody" | |
| Settings → Privacy Shortcuts | Who can see your posts? → Friends only. Who can find you? → Friends of Friends | |
| Settings → Account → Private Account | Toggle on: Private Account. Only approved followers see your content. | |
| TikTok | Settings → Privacy | Private Account ON. Direct Messages → Friends only |
Misinformation is false or inaccurate information shared — sometimes innocently, sometimes deliberately — online. In Nigeria, health misinformation is widespread on WhatsApp and Facebook, including false claims about drugs, medicines, and cures.
Before you share any health, drug, or medicine claim online, follow four steps:
altdap.com — Evidence-based drug awareness platform for Nigerian youth. Anonymous, private, and research-backed. nafdac.gov.ng — National Agency for Food and Drug Administration and Control. ndlea.gov.ng — National Drug Law Enforcement Agency. Always verify health claims with one of these before sharing.
Cyberbullying is when someone uses digital devices or platforms to intimidate, shame, threaten, or embarrass another person. It can happen through messages, posts, photos, or online gaming.
| If you are being cyberbullied | If you see cyberbullying happening |
|---|---|
| Do not reply — responding often escalates the situation | Do not join in, even to "tease" along with others |
| Screenshot and save evidence before deleting | Send a private supportive message to the person being targeted |
| Block the sender on all platforms | Report the content to the platform |
| Report to the platform using the Report button | Tell a trusted adult — teacher, parent, or counsellor |
| Tell a trusted adult immediately | If the person seems in distress, call the Emergency line: 112 |
Child Online Protection: 112 (free, works even without airtime). NDLEA Drug Helpline: 0800-CALL-NDLEA. ALTDAP AI Counsellor: altdap.com — anonymous, available 24/7.
Understanding your rights, responsibilities, and impact as a member of the digital community.
A digital citizen is someone who uses technology and the internet responsibly, ethically, and safely. Just as being a good citizen in your community means following rules and treating others with respect, being a good digital citizen means applying those same values online.
Every time you go online — search, post, like, comment, stream — you leave a trace of data called your digital footprint. This information can be seen by platforms, employers, universities, and others, sometimes years later.
Ask yourself: Would I be comfortable if my teacher, parent, or future employer saw this? If not — do not post it. Deleting a post does not mean it is gone; it may already have been screenshotted or shared.
| Responsible | Irresponsible |
|---|---|
| Verify information before sharing | Forwarding unverified health claims or rumours |
| Ask permission before tagging or posting someone's photo | Posting someone's private photo without consent |
| Disagree respectfully, using facts | Insulting, mocking, or threatening others online |
| Report harmful content using platform tools | Ignoring or encouraging cyberbullying |
| Acknowledge sources when sharing information | Presenting others' work or ideas as your own (plagiarism) |
| Use your real identity and take accountability | Creating fake accounts to harass or deceive others |
Copyright protects the work people create — articles, photos, music, videos, and code. Using someone else's work without permission or credit is a violation of copyright law, even online.
Plagiarism is presenting someone else's words or ideas as your own. In education and professional life, this can result in serious consequences.
Nigeria's Nigeria Data Protection Regulation (NDPR), administered by NITDA, gives you rights over your personal information. Key rights include:
Most apps and websites require you to accept their Terms of Service. Few people read them. Key questions to ask: What data do they collect? Who do they share it with? Can you delete your account and data? If a service seems to require too much personal information for what it offers, consider whether it is worth using.
If you or someone you know is struggling with substance use, mental health, or personal safety, these Nigerian resources offer safe, confidential online support:
| Resource | What It Offers | How to Access |
|---|---|---|
| ALTDAP | Drug awareness, anonymous self-check, AI counsellor, 90-day recovery programme | altdap.com — completely anonymous, no account needed |
| NDLEA | Drug law enforcement, rehabilitation referrals | ndlea.gov.ng or 0800-CALL-NDLEA |
| Emergency | Police, fire, medical, child protection | 112 — free, works without airtime |
| NAFDAC | Verify registered drugs and report fake medicines | nafdac.gov.ng or 0800-900-9999 |
Digital citizenship is not only about avoiding harm — it is also about actively contributing to a safer, kinder, and more informed digital community. As someone who has now completed this training, you have skills that many people around you do not yet have.
By completing all 11 chapters — including this Digital Safety unit — you have demonstrated the knowledge and responsibility expected of an ALTDAP Digital Citizen. Visit altdap.com to complete the Awareness Challenge and earn your full Dual Badge. Your digital skills are your first line of defence — online and in real life.
Your official certificate is issued by your trainer after reviewing your quiz results. Complete all 11 chapters, then notify your trainer below — they’ll confirm your results and print your personalised certificate.
Send your quiz results directly to your trainer so they can record your completion.
Share the card on social media, or send results directly to your trainer at altdap1@gmail.com / WhatsApp +234 703 051 5183.
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