CompTIA Certification A+ Exams: Installing, Removing, and Repairing Applications

To properly maintain and diagnose applications, an A+ Certified Professional must be able to manage the installation and removal of applications. Before you can work with applications on your computer, you need to install them. With the rate at which the computer industry changes, you cannot avoid the need to upgrade or remove applications on your computer as they become obsolete.

The terms app, application, and program are synonymous: They all refer to programming code that performs a function. Here, though, the term application describes the programming code that represents the functions you want installed on your computer — like a word processing application or a game. The term program describes the programming code that allows you to install the application. And when referring to applications purchased from the Windows Store or applications that run on mobile devices, the term app is used.

How to install an application

Most applications come with an installation program that must be run to install the application. Some applications (say, the terminal emulation program PuTTY) are actually stand-alone applications that do not require extra files and settings to be created on your computer, but these are rare. Most applications require several files to be installed and often require Registry entries to be created to hold the settings for the application. Because of the complexity involved in copying the files and creating the settings, you use the installation program to ensure that the application is installed properly. The application’s developer decides the name of the setup program, which in many cases is setup.exe or install.exe.

Before installing a new application, you should ensure that your computer or device meets the hardware or system requirements related to drive space and RAM. If your device does not meet the requirements, you may find that the software will not perform as expected on the device. The setup program will verify that the hardware and system requirements are met before installing the program. In those cases when the requirements are not met, the setup program can prevent the application from being installed.

In addition to hardware requirements, the application may have similar requirements related to the OS installed on your computer or device. This may be the case if your device is running Windows 7 and the software requires that the OS is Windows 10 or above. In these cases, you may manually check to verify your OS is supported by the application, but the setup program may also prevent the application from being installed.

In most cases, a user needs administrative rights in order to install an application. When installing an application, you usually need to put files in or make changes to the following locations:

• C:\Program Files
• C:\Program Files (x86)
• C:\Windows
• HKey Local Machine\Software

All of the places listed here have default permissions that restrict normal users from making changes to them. This by itself will be enough to prevent normal users from installing software. If the rights for these locations are modified, then a typical user would be able to install most software.

There are exceptions to user installation permissions. The Opera browser is one such example. When installing the Opera browser, if a user does not have rights to the previously mentioned locations, the setup program installs the files or the users’ AppData directory and writes all registry entries to HKey Current User.

Controlling software installation and restricting users from freely installing software adds security to the computers you are managing. If users are able to freely install software, they may make poor choices related the safety of the software they install, or they may choose to install software that is not compliant with your company’s security policies. Poorly written software may inadvertently or purposefully cause performance issues on the device on which it is installed, or worse yet, it may over-saturate network connections and impact network performance. These impacts can have a detrimental effect on your ability to perform work. If these applications have a malicious intent, then it may have a dramatic impact on your personal or corporate data as well.

Very few installation programs work in exactly the same way. In general, though, you are asked for the location where you want the application installed. Other options, such as whether you want to create a desktop shortcut to the application or whether you want a specific option to be enabled, are application specific.

There are several ways to install a program on your computer, but each basically runs the installer program. The following options are available from which programs may be installed:

• Local Optical disc (DVD-ROM or CD-ROM)
• Local Flash drive or USB device
• Internet
• Network

Windows 8 adds the option to also install software from the Windows Store. Windows Store applications differ from other applications as they are accessed via the Windows Store and are packaged in an .appx file format.

To install an application from the network, you can locate an install program on a network share, or you can use the Programs and Features Control Panel. To use the Program and Features Control Panel on a Windows 8.1 computer, use the following process:

1. Right-click Start and choose Control Panel.
2. Click Get Programs. If the Get Programs link is not present, it is because your computer is not part of Active Directory. The Get Programs screen will list any programs which are published through Active Directory or from other network sources, such as Microsoft’s System Center Configuration Manager.
3. Select a published application and click the Install button. The installation process for the application begins.

Many applications are distributed on CD-ROM, DVD-ROM, downloaded from a website, or a web service, like the Windows Store. For software shipped on an optical disc, when you insert the disc into your optical drive, Windows searches for an autorun.inf file and launches the program specified by the autorun.inf file. In most cases, the specified program is the application setup program if the application is not already installed. This AutoPlay feature of Windows makes installing applications even easier.

If you are using Windows 8.1, you have the option of installing an application from the Windows Store. These applications are published to the store by the application developer and are either free or available for online purchase. To install an application from the Windows Store, follow these steps:

1. Click Start. The Start screen opens.
2. Click the down arrow in the circle in the bottom-left corner of the screen. A list of all the applications installed on your computer appears.
3. Click the Store icon in the S section of the listing. This launches the Store application. At this point you may use the Search bar in the top-right corner of the screen to look for an application or scroll through the collections, top charts, and categories of applications for the app you are interested in installing.

   You may also find the Store icon pinned to the Taskbar or the Start screen.

4. Select the application you want to install. The details regarding that application will be listed. If it is a purchased application, a Buy button appears; otherwise you will see an Install button.
5. Click the Install (or Buy) button to install the application. If this is the first application you have installed, you will be asked if you want to set up a payment method for future purchases, even if the current application is free.
6. Move your mouse to the top of screen to activate the Title bar, and click the X in the top-right corner to exit the Store.

How to uninstall an application

Most applications also provide a program to uninstall the application when you no longer want it on your hard drive. The path to the program and any switches that are required for it to function are usually stored in the Registry during the installation of the application.

Always use care when working in the Registry; improper changes can leave you in a position where you will be required to re-install the OS.

The procedure to uninstall or remove a program from a Windows computer is very easy. After opening the Programs and Features Control Panel applet and clicking Uninstall a Program, select an installed application from the list, as shown in the following figure. You are provided details about that application, such as its size and when it was installed. In addition, you will see three buttons above the list of applications: Uninstall, Change, and Repair. To change the installed components of an application, click the Change button; to remove the application, click the Uninstall button. Some applications will have a Change/Remove button, which will then allow you to make changes to the list of installed components, or to remove the application; it uses the same program to accomplish both tasks. Windows looks up the name of the uninstallation program to run in the Registry and executes it.

Like the installation procedure, there is no set uninstall procedure, and it is left up to the software developer to design the uninstall routine. Some developers do an excellent job, and others do not. In the case of applications that do not uninstall properly, you might find the icons, files, or Registry entries still present after the uninstall program has completed. If that is the case, manually remove the leftover components.

In many cases, applications are removed by using special options with the setup program that originally installed them. One nice feature of using the setup program is that many developers allow you to not only remove the application, but also to change the components that are installed.

How to repair an application

From time to time something will happen to an application, be it user error or a system error. Whatever causes the problem is less important that the cure, and that is the application repair process. This process can easily be accessed via the Program and Features Control Panel using the following process on a Windows 8.1 computer:

1. Right-click Start and choose Control Panel.
2. Click the Programs link. Programs opens and displays the Programs and Features link.
3. Click the Uninstall a Program link. A list of programs that can be uninstalled or changed appears.
4. Select a program that presents a Change option and then click Change. The application launches the setup program, which allows you to change, repair, or re-install the application.
5. Follow the Repair Wizard options until the repair is complete.

Make sure that you are familiar with the standard method of adding and removing applications from your system through the Programs and Features Control Panel.