Operating System, Application and Utility Software
Senior 3 · ICT
Operating System, Application and Utility Software
Lesson 5 of 5
25 min
The school has received three new laptops with only Windows on them. Before the S3 class can use them, someone must install an office suite and a second web browser, check that an antivirus is protecting them, add a spelling extension to the browser, and remove a trial program that came pre-installed. In S1 you learned the golden rule: install only from official sources and read every screen. This lesson is the full procedure, step by step, the way a technician does it.
Definition
Installation: copying a program's files onto a computer and registering it with the operating system, so that it appears in the Start menu, opens its file types and can be updated and removed.
Installer (setup program): the program that performs an installation, usually as a setup wizard, a series of pages with Next and Back buttons. On Windows it is usually an .exe or .msi file.
User Account Control (UAC): the Windows prompt "Do you want to allow this app to make changes to your device?". Installing for all users needs administrator approval here (S2: user accounts and privileges).
.msi file. Open your Downloads folder and double-click it.A third way is the Microsoft Store: search for the app and click Get or Install. Store apps are checked by Microsoft and update themselves.
Figure 1. Mock-up of a setup page for an imaginary program. The Typical choice is fine, but the ticked box would also install an unwanted toolbar and change the browser's home page. Untick it before clicking Next.
Definition
Bundled software (potentially unwanted program): an extra program offered inside another program's installer, often ticked in advance, such as a toolbar or a "PC optimiser". It is not always malware, but it is rarely wanted.
Add-on: a small program that adds a feature to a host application and runs inside it. Browsers call them extensions, Microsoft Office calls them add-ins, and other programs say plug-ins. Example: a spelling and grammar extension for Firefox.
| Host application | Where to find add-ons | Where to remove them |
|---|---|---|
| Firefox | Menu ☰ → Add-ons and themes (the official site is addons.mozilla.org) | Same page → the add-on's ⋯ → Remove |
| Microsoft Edge | Menu ⋯ → Extensions → Get extensions for Microsoft Edge | Extensions → Manage extensions → Remove |
| Google Chrome | Chrome Web Store | Menu ⋮ → Extensions → Manage Extensions → Remove |
| Microsoft Word | Home → Add-ins (in some versions Insert → Get Add-ins) | The same Add-ins window → My Add-ins |
| LibreOffice | Tools → Extension Manager → Get more extensions online | Extension Manager → select → Remove |
An add-on can be very useful: a dictionary, a grammar checker, a reference manager. But a browser extension may ask to "read and change all your data on all websites", which includes passwords and messages you type. Before adding one, check the publisher, the number of users, the reviews and the permissions it asks for, and keep only the few you really use.
Worked example 1: add it or not?
Gatete wants a free "PDF Converter Pro" browser extension. Its page shows: an unknown publisher, 140 users, an average rating of 2.1 out of 5, and the permission "Read and change all your data on all websites".
Decision: do not install it. The benefit is small, an existing program already does the job, and the permission gives it access to his passwords.
You met the antivirus's role in S2: it scans files, watches programs in real time, quarantines threats and needs frequent definition updates. Windows 10 and 11 already include one, Microsoft Defender Antivirus, so the first job is to check, not to install.
Windows Security and open it. Click Virus & threat protection.If the school has bought a different antivirus, install it like any program, but only from the maker's own website or the installer the school supplies. Restart if asked, let it download its latest definitions, then run a scan. Windows then switches Defender's real-time protection off by itself, and Windows Security shows the new product's name as the active provider.
Warning
One real-time antivirus at a time. Two antivirus programs scanning together slow the computer and can block each other. And beware of fake antivirus: a pop-up saying "Your computer is infected! Download our scanner now" is itself the threat. Close the browser tab; do not click inside the pop-up.
Figure 2. Mock-up of Settings → Apps → Installed apps in Windows 11, with the ⋯ menu of one program opened.
Two other routes: click Start → All apps, right-click the program and choose Uninstall; or the older Control Panel. The Control Panel route still works: Control Panel → Programs → Programs and Features, select the program, click Uninstall. On an Android phone, open Settings → Apps, tap the app and tap Uninstall.
Warning
Never "uninstall" by deleting the program's folder. Deleting a folder in C:\Program Files leaves the program registered with Windows, with broken shortcuts and leftover settings, and it can no longer be removed properly. Always use the uninstaller. Your own documents are not removed by an uninstall, so save them elsewhere if you no longer want them on the computer.
Windows 11 includes winget, the Windows Package Manager, which installs and removes programs with typed commands (a CLI, as in Lesson 1). A technician preparing 30 lab computers can run the same commands on each one.
Type these in Command Prompt or Terminal. search lists matching programs and their IDs; install downloads the program from the source listed in winget's catalogue and installs it; uninstall removes it. The -e option means "exact match", so winget does not pick a program with a similar name.
Worked example 2: preparing a lab computer
Put these jobs in a sensible order: install Firefox; uninstall the pre-installed trial program; check Windows Security; install LibreOffice; add a grammar extension to Firefox.
The two rules: protection before downloads, and a host application before its add-ons.
Tip
Memory hook for installing: S-R-R-L, then read every screen. Source, Requirements, Rights, Licence. For removing: always through the uninstaller, never by deleting folders.
Practice
Further reading
Sources and credits
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
winget search firefox
winget install --id Mozilla.Firefox -e
winget uninstall --id Mozilla.Firefox -e