The Role of Applications | PC Disaster and Recovery

Regardless of how you use your computer, applications are the meat and potatoes of your PC. Just as an operating system helps your PCs work, your applications help you work, providing an interface to create your documents and files, manipulate images you capture from a digital camera or scanner, write a piece of music, or even play a game (yes, even games are applications).

In the computer industry, applications are called end-user software because they are typically designed to be (relatively) easy to use by someone regardless of his or her level of knowledge of the PC.

Let’s dig a bit deeper.

What an Application Is

An application can be either a single program (for example, Microsoft Word) or a suite of related programs tied together into one package (for example, Microsoft Office) that is designed to let you learn, produce, look up information, or have fun.

What an application can’t do is run entirely on its own; it needs an operating system to run. Applications are written for specific platforms, meaning types of computer setups. Examples of two different platforms are Windows Consumer (Windows 95/98/Me/XP Home Edition) and Windows Professional (Windows NT/2000/XP Professional). The majority of people today use the Windows Consumer platform, so it’s not surprising that most applications are written to run under Windows Consumer.

These programs usually focus on a particular area and include these major types of products:

Word processors
Databases
Spreadsheets
Almost anything else that isn’t a system tool

Note

Is an operating system an application? No. Most software is divided into two main categories: system software and application software. System software is any type of software or utility that acts to specifically control or manage the PC itself. This includes operating systems and PC utility packages, as well as essential programming tools for software developers. An application, by contrast, cannot run on its own without an operating system.

How an Application Installs

It’s easy to take for granted the process of installing a new application to your Windows PC because—as with other elements discussed in this book—so much happens that you won’t normally see. You’ll learn more about these hidden tasks in the next section on integration. Right now, let’s look at the typical steps when installing an application. These are:

Run the application’s Setup.
Setup launches an installation wizard that helps you configure the way you want the application to reside on your system (for example, in what folder it should install itself).
Setup checks to make sure your system meets the minimum requirements for its installation, that you have enough hard drive space and memory available, that your CPU is powerful enough, and that you’re running a compatible operating system.
Setup looks to see if another version of this program is already on your system. If it finds one, it asks if you want to install this new version as an upgrade, completely updating your current application.
Setup may also check to make sure that core Windows files are present in case they need to be installed or reinstalled (see the next section, “How an Application Integrates”).
Setup begins preparing your system to accept the application and begins copying files from the disk or CD.
The application is registered with one or more entries into your Windows Registry.
Once everything is copied, Setup asks you whether you want to add this application to a specific group (for example, Games), and whether you want it to come up on startup, meaning that each time Windows reloads, the application will automatically load on the desktop.
Setup notifies you that the installation is successful and that it is now ready to use.

How an Application Integrates

Many if not most Windows applications are developed using certain program development standards that take into account the common files, features, and functions of the Windows operating system. The developers try to match the keystrokes and overall characteristics of major functions (such as printing) throughout all the applications you can install and run. In this way, you can press Ctrl+P in many different applications to initiate printing or Ctrl+O to open files.

Remember how you’re always warned to close all other programs before you install a new piece of software? Many people ignore this advice, but the need to close other applications is apparent once you understand the complexity of an application installation.

As I said, these applications are based on something called the Windows Application Programming Interface (API) that try to take advantage of what is already in Windows to help them install and work. The applications may be looking to access or even modify certain core files installed and used as part of Windows—as well as by other applications—as the application installs. If other applications have these core files open, the files may be locked so that the new application can’t use them and then can’t install properly. If the new application isn’t locked out of these files, some confusion can result because two applications are trying to use or modify the same files at the same time. For this reason, you and your PC are better off if you close all other applications before installing a new one.

You should also know that applications don’t always install in a tidy fashion. By this, I mean that an application doesn’t just install itself to its own program folder, although it does that, too. Many applications copy files to a number of different locations, including to main folders under Windows. This can make it very difficult for even an experienced technician to hunt down every file associated with a particular application.

Another example of integration is seen in the Windows Registry, because information about the application, the types of files the application works with, and the way you’ve configured the application to work is stored to entries in the Registry. It’s for this reason that you don’t just delete applications you no longer want; you must uninstall them using the Add/Remove Programs icon in Control Panel, and follow the wizard to select the application components you want to remove.

Of course, there’s a significant benefit from the application’s integration into the Registry. For one, other applications may be able to work in correlation with your new application. For example, Word 2000, when I need to add a document to it that I have digitized using my flatbed scanner, automatically knows to load my scanner interface application to help me accomplish this task. Also, when you go to open a file used by the new application, you’ll find that Windows has registered—in the Registry—the types of file formats the new application will work with. Thus, you simply click the file to open it and Windows knows to automatically load the application registered to work with that file format.

The message to take from all of this is (again) that your PC as a whole—from hardware to software to operating system—is a composite of everything you’ve installed to it. Take care not to take actions that seem like they solve one problem when they may create other problems. After all, you don’t want to create a disaster or compound an existing one.