A Beginner’s Guide to Desktop Application Testing (With Examples)

 

Starting with Desktop Application

What is a Desktop App?

A Desktop Application (Desktop App) is a software program designed to run on a personal computer (PC) or laptop within an operating system like Windows, macOS, or Linux. Unlike web applications that run in a browser, desktop apps are installed on a computer's local storage and run directly on the operating system.

Types of Desktop Applications

• Standalone Applications – Work without an internet connection (e.g., MS Paint, Notepad).

• Client-Server Applications – Require internet or a network to function (e.g., Microsoft Outlook, Skype).

• Hybrid Applications – Work both online and offline with cloud integration (e.g., OneDrive, Dropbox).

Examples of Desktop Applications

• Utility Software: CCleaner, PC Optimizer

• Productivity Apps: Microsoft Word, Excel

• Media Players: VLC, Windows Media Player

• Development Tools: Visual Studio, Eclipse

What is Desktop Application Testing?

Desktop Application Testing is the process of evaluating a desktop application to ensure it functions correctly, meets user requirements, and is free from defects before release. This involves testing the app’s functionality, performance, security, and user experience on different operating systems and hardware configurations.

Types of Desktop App Testing

• Manual Testing – Testers manually execute test cases without automation tools.

• Automation Testing – Uses scripts and tools to automate repetitive test cases.

Key Areas of Desktop Application Testing

• Functionality Testing – Ensures the app performs expected tasks (e.g., opening files, saving data).

• UI/UX Testing – Checks layout, fonts, colors, and user interactions.

• Performance Testing – Evaluates app speed, CPU/memory usage, and load handling.

• Compatibility Testing – Verifies the app works on different OS versions and screen resolutions.

• Installation & Uninstallation Testing – Ensures smooth setup and removal of the app.

• Security Testing – Checks for vulnerabilities like data breaches or unauthorized access.

Example Scenario: Testing a PC Optimizer App

• Functionality: Does the app detect junk files correctly?

• Performance: How much CPU/memory does it use during scanning?

• Installation: Does it install correctly without errors?

• Security: Does it ask for unnecessary admin permissions?

Basic Understanding Needed for Desktop Application Manual Testing

To become proficient in Desktop Application Manual Testing, you need to understand the fundamentals of software testing, desktop environments, and testing strategies.

Basic Knowledge of Desktop Applications

• How Desktop Apps Work – Installed on a PC, runs on an OS (Windows, macOS, Linux).

• Types of Desktop Apps – Standalone, Client-Server, Hybrid.

• File System & Registry Understanding – How apps store data in local files and system registry.

• Common Desktop App Issues – Installation failures, crashes, UI glitches, performance lags.

Tools & Skills to Learn

• Basic OS Knowledge – Windows file system, Task Manager, Command Prompt.

• Basic Performance Monitoring – Checking CPU, Memory, and Disk Usage via Task Manager.

How Desktop Applications Work?

A desktop application is installed on a PC and runs within an operating system (Windows, macOS, Linux). Unlike web applications, it doesn’t require a browser to function.

Example:

• MS Word: Runs on Windows/macOS without needing a browser.

• VLC Media Player: A media player installed on your system, running locally.

• Google Chrome (as a desktop app): Installed on your computer but connects to the internet for browsing.

How to Learn:

• Install any desktop app (e.g., Notepad++, VLC).

• Observe how it behaves when launched, minimized, maximized, or closed.

• Check if it requires an internet connection.

Types of Desktop Applications

There are three main types:

Standalone Applications

• Work without an internet connection.

• Data is stored locally on the PC.

Example:

• Notepad: Can open, edit, and save files without internet.

• MS Paint: Allows you to create images offline.

Client-Server Applications

• Require an internet connection to communicate with a server.

• Data is stored on both the client-side (PC) and server-side (cloud).

Example:

• Microsoft Outlook (connected to email servers): The app stores emails locally but syncs with an online server.

• Skype: Requires internet but runs as a desktop application.

Hybrid Applications

• Can function offline but has enhanced features when connected to the internet.

Example:

• Google Drive (Desktop App): Allows offline file access but syncs changes online when connected.

• Spotify: Can play downloaded songs offline but needs the internet for streaming.

How to Learn:

• Install MS Word and Google Drive on your system.

• Test opening files offline and online.

• Observe how a Client-Server app syncs data with the cloud.

File System & Registry Understanding

Desktop apps store data on the PC either in files or the Windows Registry (for Windows users).

Example:

• Install Notepad++ and check where it stores configuration files.

• Open Task Manager and see how apps use CPU/memory.

• Windows Registry Example: Open regedit and search for installed app data.

How to Learn:

• Install CCleaner and observe how it detects junk files.

• Use File Explorer to locate where apps save their logs/config files.

Common Desktop Application Issues

Every desktop app can experience issues such as installation failures, crashes, UI glitches, or performance problems. Below are common issues and their solutions:

1. Installation Failure

Scenario: An app installer fails due to missing dependencies.
Example: While installing Adobe Photoshop, it asks for specific .NET or Visual C++ packages.
Solution: Install the missing dependencies and try again.

2. Crashes & Freezes

Scenario: The app stops responding while running.
Example: MS Word crashes when opening a large document.
Solution: Check system RAM usage, close unnecessary programs, and restart the app.

3. UI Glitches

Scenario: Buttons or text appear broken.
Example: In Skype, the call button is misaligned after an update.
Solution: Restart the app, check resolution settings, or update the app.

4. Performance Issues

Scenario: The app uses high CPU or memory.
Example: Google Chrome consumes excessive RAM, slowing down the PC.
Solution: Close unused tabs, clear cache, and check Task Manager for resource usage.

How to Learn:

• Try installing and uninstalling software (observe logs).

• Use Task Manager to monitor app performance.

• Experiment with high-load apps (e.g., running Photoshop with multiple files).

Types of Desktop Application Installers

A Desktop App Installer is a package that helps install a desktop application on a computer. There are different types of installers based on structure, packaging format, and installation process.

Types of Installers Based on Structure

1. EXE (Executable) Installer

• Most common format for Windows applications.

• A single executable (.exe) file that launches the installation process.

• Can be standalone or a self-extracting archive.

Example:

• chrome_installer.exe (Google Chrome)

• vlc.exe (VLC Media Player)

2. MSI (Microsoft Installer Package)

• Windows installer format managed by Windows Installer Service.

• Used for structured installations with built-in repair and uninstall options.

• Suitable for enterprise deployments (e.g., silent installations).

Example:

• ZoomInstallerFull.msi (Zoom)

• AdobeReader.msi (Adobe Reader)

3. DMG (Disk Image) - macOS Installer

• Used for macOS applications.

• Contains app files and a drag-and-drop interface to install apps.

Example:

• GoogleChrome.dmg

• Skype.dmg

4. PKG (Package Installer) - macOS Installer

• Used for installing software in macOS with system-level changes.

• Common for applications that require deeper system access (e.g., drivers).

Example:

• MicrosoftOffice.pkg (Microsoft Office for macOS)

5. APPX & MSIX (Modern Windows Installers)

• Used for Windows Store apps and modern software deployment.

• MSIX is the newer format replacing APPX.

• Secure, supports auto-updates, and integrates with Windows security features.

Example:

• Spotify.appx (Windows Store version of Spotify)

• YourApp.msix (Universal Windows Platform - UWP apps)

Types of Installers Based on Installation Process

1. Online (Web-Based) Installer

• Small-sized installer that downloads required files from the internet.

• Requires an active internet connection.

Example:

• chrome_installer.exe (Downloads Chrome from Google servers).

• SkypeSetup.exe (Downloads full Skype package online).

2. Offline (Full) Installer

• Contains all required installation files.

• Does not require an internet connection after download.

Example:

• vlc-setup.exe (VLC Media Player full installer).

• AdobeReader.msi (Full offline Adobe Reader package).

3. Portable Applications (No Installer Needed)

• No installation required; runs directly from a folder or USB drive.

• Leaves no changes in system registry or Program Files.

Example:

• Notepad++ Portable.exe

• CCleaner Portable.exe

Admin vs. Non-Admin Installation of Desktop Applications

When installing a desktop application, it may require either Administrator (Admin) privileges or Non-Administrator (Standard User) privileges.

What is an Admin Installation?

An Admin Installation requires Administrator privileges to install the application on the system. This allows the software to make system-wide changes, install drivers, and modify system settings.

Key Characteristics:

• Requires Admin rights (User Account Control - UAC prompt in Windows).

• Installs software in system-level locations (C:\Program Files or C:\Program Files (x86)).

• Can modify Windows Registry, System Files, or Services.

• Accessible by all users on the PC.

• Used for enterprise, security, or system-level applications.

Real-Time Examples:

• PC Optimizer

• Adaware Privacy

• Antivirus Software (McAfee, Norton, Windows Defender)

• Database Software (MySQL, Microsoft SQL Server)

• VPN Software (NordVPN, Cisco AnyConnect)

What is a Non-Admin Installation?

A Non-Admin Installation does not require Administrator privileges and is installed only for the current user. It does not modify system files or registry settings.

Key Characteristics:

• Does not require Admin rights (no UAC prompt).

• Installs software in User-Specific Locations (C:\Users\Username\AppData\Local).

• Can only be accessed by the user who installed it.

• Cannot modify system settings or install system drivers.

Real-Time Examples:

• Google Chrome (User-Specific Install)

• Zoom (Non-Admin Install)

• Spotify Desktop App