The Computer Operating System
Why You Need an Operating System
A computer is a massive productivity tool on steroids. It can help you find new information about any topic
you want to learn more about. It can show you the layout of your geographical area or far-away
destinations that you want to visit one day. It can help you create that business report your boss wants
and print it to a printer that is directly attached to your computer or is located near your boss’s office. It
can help you stay in touch and communicate with members of a work team or your relatives through
applications such as email, Lync, or instant message. In fact, it can host dozens of applications that you
can utilize for work or entertainment. There are so many things that a computer can do, but in order to
accomplish these things, it needs a way for you to interface with it so that you can issue a command or
series of commands to instruct the computer what it is you want it to do. This is the primary purpose of the
operating system.
The operating system also provides the ability for peripheral devices to be integrated with the computer. If
you have ever installed a new printer or external device to your computer, you have noticed that the OS
requires a driver to be installed. This driver is the liaison between the device and the operating system so
that the two can communicate with one another. Once installed, the user can access the printer or newly
installed device through the OS.
For more information on the purpose of a computer’s operating system go to
http://en.wikipedia.org/wiki/Operating_system.
The History of the PC Operating System
An operating system provides an interface for you to interact with the computer. In the beginning of the
era of the PC, the interface was simply a black screen provided by an operating system called DOS,
which stood for Disk Operating System. It was Microsoft’s first operating system and was released in
1986. Users could type commands at a computer prompt to have the computer perform various tasks.
DOS looked pretty much like the Command Prompt utility of Windows today.
This was a very primitive operating system and required users to memorize or have access to a list of the
available commands in order to navigate their local files or perform basic tasks. Because of this, the
market for the PC was limited, as many people felt intimidated by this interface. Even among highly active
DOS users, few people knew all of the available commands. A new interface was needed in order to bring
the true potential of the PC to a broader market of users.
Windows 3.1 was released by Microsoft in 1992. It provided a GUI, or Graphical User Interface system.
Although it was crude by today’s GUI standards, it integrated the input device that we commonly refer to
today as the mouse, which allowed users to easily navigate across the screen and access files and
accessories with the simple click of a mouse.
This was followed up by Windows 95, named after the year of its release. It had a redefined look that
became the template for all of its operating systems up until Windows 7. It was also Microsoft’s first
16/32-bit hybrid operating system.
This was followed up by its even more popular Windows 98 which was released in its titled year. This was
followed up by Windows Millennium in the year 2000 which failed to capture much interest within the
marketplace. This was also the last OS of the Windows 95 lineage.
One of the confusing aspects in the history of the Windows operating system is the dual line of operating
systems that Microsoft supported for almost a decade. Windows 3.1, 95, 98, and Millennium were
consumer-driven operating systems. They had no built-in security. You didn’t even need a
username/password to log on. This lack of security along with the lack of a true 32-bit operating structure
prevented it from being a viable enterprise-level operating system. This was the reason why in 1993,
Microsoft released Windows NT. Windows NT came in two versions, NT Server and NT Workstation.
Microsoft then released Windows 2000, again in both a server and workstation version, and began
obtaining market leadership in the enterprise market. Windows 2000, XP, Vista, Windows 7, and
Windows 8 are all members of the NT family. The consumer-driven line of operating systems was
abandoned with Millennium once Windows XP was released in 2001 as the upgrade to Windows 2000. At
the time of this writing, XP continues to be prominently utilized despite its being more than 10 years old.
This is partly due to its upgrade, Windows Vista, which proved to be a PR disaster for Microsoft as it
garnered a reputation as being buggy and awkward to use in some instances. This was followed up by
Windows 7, which revamped the Microsoft name and provided a very dependable and secure OS that
users appreciated. At the time of this writing, Microsoft’s latest OS is Windows 8, which is Microsoft’s
attempt at creating a universal operating system for just about any type of computing device, be it a
desktop, laptop, tablet, or smartphone. The verdict is still out regarding whether this approach will prove
to be successful.
You will also see that XP, Windows 7, and Windows 8 come in different versions as well, such as Home
Edition, Professional Edition, and Ultimate Edition. The difference between these versions is the variety of
features offered by them. While Home Edition is usually more than suitable for the average home user, it
lacks the features required by a work or enterprise environment.
You can read more about the Windows 8 operating system at http://windows.microsoft.com/enus/windows-8/meet.
32-bit and 64-bit Operating Systems
Today’s operating systems can come in 32-bit and 64-bit versions. The terms 32-bit and 64-bit refer to
the way a computer's processor handles information. Most new computers available for purchase today
are 64-bit machines, but if you have a choice between 32-bit and 64-bit machines, you should always go
with the 64-bit machines if you can.
The number of bits refers to the width of the CPU’s register. The register is a small amount of storage
used by the CPU where the CPU keeps the data it needs to access the quickest in order for optimum
computer performance. The bit designation refers to the width of the register; thus a 64-bit register can
hold more data than a 32-bit register which in turn holds more than 16-bit and 8-bit registers. The more
ample the space in the CPU’s register system, the more it can handle, especially in terms of utilizing
system memory.
The primary advantage of 64-bit machines is the greater amount of memory that they support. All 32-bit
operating systems can only support up to 4GB of memory. The Windows Home editions of 64-bit
operating systems can support up to 16GB of memory, while the Professional and Ultimate versions can
support up to 192GB which is more than a workstation would ever need. What’s more, it reserves less
memory which frees up more memory to your applications. For this reason, a 64-bit machine can run
more applications simultaneously with improved performance.
A 64-bit application won’t install on a 32-bit application, but most 32-bit applications will install on a 64-bit
computer. You should also keep in mind that these two architectures require a different driver set. If you
purchase a computer with a 64-bit operating system, you can’t use the same driver you installed with your
former 32-bit operating system.
To determine if your computer is running a 32-bit or 64-bit OS, simply access the system properties in
your Windows computer. An example is shown below.
You can read more about the 64-bit operating system at http://en.wikipedia.org/wiki/64-bit_computing.
Servers Operating Systems
As mentioned, Windows NT came in two versions, one of them being NT Server. From that operating
system came Server 2000, Server 2003, Server 2008, and Server 2012. The desktop of one of these
server operating systems looks much like that of a workstation at first glance, but there are vast
differences between the two operating systems. A workstation OS such as XP or Windows 7 is designed
to create a computing platform for a single user, as only one user can log on to a workstation at a time.
Although they can share a printer or file directory with remote users, these operating systems are limited
in the number of simultaneous connections they can support (XP can support 10 remote connections,
while Windows 7 can support 20). Even a robust desktop has hardware limitations when it comes to
memory, volume size, and processing speed, which puts definite limitations on its ability to share
resources with remote users.
A server is designed with the specific purpose of sharing resources with remote users. A resource can be
a group of files, an application, a series of printers, or an Internet connection. Because of this, server
operating systems such as Windows Server 2008 and 2012 are built to support vast amounts of memory
and file storage as well as extremely fast processors. They are also built with redundancy in mind.
Servers often have redundant power supplies, hard drives, and network interface cards so if one power
supply goes down, the system remains up. Should a single hard drive fail, no data is lost and users can
continue to access hosted files and applications. Although Microsoft Server operating systems can be
utilized as a user desktop, most servers reside in a datacenter and are rarely accessed by anyone other
than a network administrator who may be installing new applications or troubleshooting a server problem.
A software license for a server operating system is much more than that of a workstation. Servers are
often licensed by the number of connections they will support.
You can download the Windows Server 2012 operating system at http://technet.microsoft.com/enus/evalcenter/hh670538.aspx for a free 30-day trial period.
Up-to-date information on Server 2012, the latest server operating system, is found at
http://www.microsoft.com/en-us/server-cloud/windows-server/.
Logging onto the Operating System
One of the things you will discover in this class is that there are many ways to navigate the operating
system. How you decide to access your applications and configure menus and files is all a matter of
preference.
After you first power the computer on, you will most likely be asked to log on with your credentials. This
consists of a username and a password. A good password should consist of at least seven characters or
more and should consist of a combination of alpha and non-alphanumeric characters. You should also
consider using multiple cases for your letters. Some good examples of a password would be the
following.
 w1nterCold
 iL0ve1T
 l0gg1nGoN
If you’ll notice, I used actual word combinations for these passwords and substituted numbers for some of
the letters. This makes it easy to remember.
An example of a logon screen is shown below; in this case, it happens to be the logon screen for the
Windows Server 2008 R2 operating system but the same idea applies.
Navigating the OS
Once you log on, you will be presented with the desktop and taskbar. The taskbar is the horizontal bar at
the bottom of your computer (you can place it at the top if you wish or at the sides but this is rarely done).
The taskbar consists of four areas:
 Start Button
 Pinned Items
 Open Applications
 Notification Area
Below is the task bar as appears with Windows 7.
The Start button allows you to access the Start Menu where nearly all of the installed applications can be
accessed. Pinned Icons are icons of frequently used applications or items. By default, Windows pins
Internet Explorer and Windows Explorer but you can manage which items are pinned at any time. Open
Applications are simply applications that you are currently running. It is very common to have multiple
applications open at the same time. The Notifications area alerts you of various real time notifications
such as the arrival of Windows Updates or new email messages.
You access the Start Menu by left-clicking the Start Button. In Windows 7 you are presented with a start
menu as is shown below. Windows automatically displays the most common applications in random
order. Below is a typical Windows 7 Start Menu. The arrows at top point to applications that are pinned to
the Start Menu. Applications that are pinned to the Start Menu are always present at the top.
By left-clicking “All Programs” at the bottom, you can then access the complete listing of installed
applications. If you have a lot of applications, you will have to scroll down to see them all.
In the example below, I have scrolled down in order to access one of the Microsoft Office 2013
applications.
You can configure various aspects of the Start Menu and Taskbar by right-clicking on either of them.
Right-clicking allows you to access the “Context Menu.” In this case the context menu presents you with
various selections including “Properties.”
Here is the context menu of the taskbar.
If you then click on “Properties,” you will be presented with this menu.
Managing Your Desktop
Besides using the traditional Start Menu to access your applications, you can also create shortcuts on
your desktop as well. Although applications are the most common examples of desktop shortcuts, you
can create a shortcut to a particular file stored on your computer or your favorite website. To create a
shortcut on the desktop, simply right-click anywhere on the desktop, select “New” from the context menu
and then select “shortcut.”
This will present you with the following screen.
Windows 8
The Start Menu, Taskbar, and Desktop Shortcuts are common among nearly all of the Windows operating
systems including Windows 7, Vista, XP, and Windows 2000. At the time of this writing, Windows 8 has
now appeared on the market. Windows 8 was designed first and foremost for touch screen tablets and
phones. For this reason, Windows 8 doesn’t have any of the traditional navigation elements we have
discussed thus far. Windows 8 has a tile based navigation system. These tiles are similar to shortcuts in
that they appear on the desktop. The user has the ability to manage the tiles.
Though this new navigation system is ideal for a touch screen device, it can take some getting used to as
a desktop operating system. For users who don’t have a touch screen and depend solely on a keyboard
and mouse, Windows 8 can be somewhat challenging. These types of users will be more accustomed to
the Desktop rather than the Start Screen that features tiles.
To easily switch to the desktop, simply ensure that the desktop tile is located in the topmost left corner of
the Start Screen.
Then simply type CTRL + ENTER. This will take the user to the desktop which will display the customary
task bar. To access the Start Screen, simply point the mouse into the far left-hand lower corner of the
desktop and click on the Start Screen icon when it appears.
Go to http://www.pcmag.com/windows-8/ for additional information on Windows 8.
Go to http://windows.microsoft.com/en-us/windows-8/rearrange-tiles-start for a more in-depth
understanding of the tile system of Windows 8.
Windows Files System
You can access your volumes and files with Windows Explorer. The three easiest ways to access
Windows Explorer are from the Start Menu, the taskbar, or by right-clicking the Start button. The
screenshot below shows Windows Explorer on a Windows 7 machine. Notice the libraries section on the
left. The library contains common folder destinations such as Documents, Downloads, Pictures, etc.
These folders are created automatically for each user who logs on to the machine. When you download
an application, the OS automatically steers it to the Downloads folder by default. When you save a picture
or image file, it is automatically saved to the Pictures folder. When you open up a music program, it
automatically looks for music in the Music folder. The library folders are a part of your user profile.
Whenever you log onto to a Windows machine, you create a profile by default. This profile contains your
library folders and the files contained within them.
The other arrow is pointed to the C drive. This is known as the System Volume in this case because it is
the volume that Windows is installed on. We know this because the Windows Directory is located on this
volume. The Windows folder contains the operating system files. Notice the Users folder above it in the
screen shot above. This is where the profile for each user who has logged on to the operating system is
located.
Notice the two folders called Program Files and Program files (x86). These are the folders that
applications are assigned to when they are installed onto the computer. You see both of these Program
Files on a computer that contains a 64-bit operating system. The folder that is appended with (x86) is
for applications that are 32-bit applications.
Folders are also referred to as directories. Folders allow you the ability to organize your volumes for file
storage. You can make your own folders by simply right-clicking anywhere within Windows Explorer
inside a volume or folder choosing New-Folder.
In order for an operating system to read your volume, it has to be formatted. All operating systems since
Windows 2000 use NTFS which stands for New Technology File System. It was a replacement for the
older DOS-based FAT (File Allocation Table) file system found on older operating systems such as
Windows 98. NTFS includes built-in security features such as file and folder permissions and encryption,
which is the technology used to store encrypted files on NTFS volumes. Only volumes that are formatted
by the operating system itself can be NTFS. Other capabilities of NTFS include the following.
 Support for volumes up to 256 terabytes in size
 Support for disk quotas and compression
 Support for mounted drives
 The ability to reconstruct files in the event of hardware failures
Below is an example of NTFS permissions for a file. Permissions include Read, Write, Modify (changing
the name of a file or deleting it), and Full, which includes all three of the former permissions and the ability
to assign permissions to other users as well.
Only a volume that is formatted by the host operating system can be NTFS. For instance, a USB stick is
formatted with FAT32 by default. However, by using Disk Manager in the Windows operating system, you
can reformat it with NTFS.
Go to http://technet.microsoft.com/en-us/library/cc754178.aspx for a greater understanding of NTFS and
share permissions within the Windows operating system.
Windows Explorer allows the user to browse volumes and directories, but today’s Windows operating
systems don’t allow users to see everything by default. Windows always tries to preserve itself from the
user whenever possible. This includes hiding critical files and file extensions from the user. For this
reason, certain files and directories are hidden from the user by default. Advanced users may want to
change this. To do so, go to Start-Run and type “Folder Options.” Doing so will display the following popup window.
Notice that there is a checkbox for “Hide protected operating system files.” By default, this setting is
unchecked as well as “Don’t show hidden files, folders and drives.” Users can also decide to display or
hide file extensions for known file types
Hardware
One of the key things that an operating system does is manage your hardware. Whether it is your
monitor, video card, sound card, mouse, keyboard or printer, the operating system needs a way to
integrate with these devices. In order for the operating system to communicate with the hardware device,
a drive specifically designed for the device must be installed. For instance, if you purchase a new printer
for your Windows 7 computer, the printer will usually come with a driver disk you can use to install it. By
default, the operating system already comes with some printers. Without the correct driver, your printer or
hardware device will not operate properly. Many times, the driver may be OS-specific as well. Just
because the driver works for a designated printer on Windows 7 doesn’t mean it will work for Windows 8.
If you suspect you have the incorrect driver for a device you can always download it from the Internet.
Most hardware manufacturers list their drivers on their websites for customers to download. You should
check now and then for updated drivers for all of your devices as manufacturers release updated drivers
now and then that fix problems and bugs that have been discovered.
Management Tools
Every Windows operating system has a management tool called the Control Panel. The control panel
allows the user to manage various aspects of the operating system such as changing the Display
properties, manage local user accounts, change the time on your compute, or install the latest drivers for
a piece of hardware. The easiest way to access the control panel is from the Start Menu. The screenshot
below shows a typical Control Panel interface.
Another common management tool is Computer Management. You can access it by right-clicking on the
“Computer” listing in the Start Menu and selecting “Management” within the context menu.
The Computer Management interface looks like this:
Here is an explanation of the listed tools in Computer Management.
 Task Scheduler – Allows you the ability to create automated tasks for your computer such as
backups or defrags.
 Event Viewer – This is where you can view the log files of your computer to find errors or clues
as to why something isn’t working correctly.
 Share Folders – You share a folder so that remote users can access it. Here you can share
folders or manage folders that are already shared.
 Local Users and Groups – Here you can manage the local user accounts contained on your
computer.
 Performance Monitor – This gives you access to Resource Monitor where you can monitor
things such as memory and CPU usage on your computer.
 Device Manager – Here you can view all of the hardware that is installed on your computer and
update your drivers.
 Disk Management – Here you can view all of the volumes on your computer, which includes
hard drives, DVD drives, external drives, and USB drives.
 Services and Applications – Your computer runs a number of services and here you can view
the status of these services.
Below is a screenshot showing what the Resource Monitor looks like.
Device Manager is a valuable tool for troubleshooting hardware problems. You can access it through
Control Panel or through System Properties.
If you suspect there is a hardware problem on your computer, you should access the Device Manager
and look for any alerts that may indicate hardware problems or conflicts. It is common to see yellow
exclamation marks.
Yellow exclamation marks usually appear due to a missing driver and, as a result, the OS is unable to
recognize the connected hardware. You may also see a red x. A red x doesn't necessarily mean there's a
problem with the hardware device. The red x simply means that Windows is not allowing the hardware to
be used and that it has not assigned any system resources to be used by the hardware.
Event Viewer has a number of logs to help you troubleshoot problems. It can be your best troubleshooting
tool in many cases. The screenshot below shows the basic log files of Event Viewer, which are the
Application log, Security log, Setup log, and System log.
If you are having problems with a certain application on your computer, you would examine the
Application log. The System log file contains events that have to do with the operating system itself. The
Security log deals with successful and unsuccessful authentication attempts. There is no technician in the
world who knows what every single log means. What you can do is copy the error or warning log and do a
web search for it to see if Microsoft has any published documentation on it or if other users have solved
this problem via a discussion board online.
Windows Registry
The Windows Registry is where nearly all of the configuration settings are stored in Windows. It is used
to store much of the information and settings for software programs, hardware devices, user preferences,
operating system configurations, and much more. Your average user has no reason to access the registry
(it requires administrative rights to access it anyway), and you should only modify registry settings if you
know what you are doing. You can access the registry by going to Start – Run and typing the command,
regedit. The registry looks like this.
The registry is critical to the Windows operating system. Go to
http://pcsupport.about.com/od/termsr/p/registrywindows.htm for more information about it.
Application Installation
There are several ways to install an application on a Windows computer. Traditionally in the past, users
installed an application from a CD or DVD that they purchased from the store. Another way is to
download the application from the Internet. As mentioned earlier, it downloads the application setup file to
the Downloads folder. You can then run the file and install the application.
As mentioned, when you install an application, many of the application files are stored within the Program
Files directory. It is these files that allow an application to integrate with the operating system. Some
applications are free and are sometimes referred to as shareware. You should know, however, that free
isn’t always free. Many times these free applications come with other applications such as web browser
toolbars and spyware applications that are used to target advertising based on your Internet behavior.
When you click on an application installation file, you are usually presented with some type of installation
wizard that takes you through the installation process. It is natural to simply click the “Next” button without
paying much attention, but you should take your time and know what you are installing to ensure that
other applications aren’t being installed as well.
Some applications allow you a trial period to try it out. This can be anywhere from 10 to 120 days. After
this trial period, you will have to purchase a license in order to run the application again. Some
applications require a license right away.
Sometimes you may need to uninstall an application. Sometimes an application will provide an uninstaller
within the Start Menu. Most of the time however, you need to go to the Control Panel and click Programs
and Features. The next screen will list all of your installed applications. Simply right-click and choose
Uninstall as shown below.
ISO Files
Sometimes when you download an application, it downloads as an ISO file. ISO stands for International
Standards Organization. An ISO file is like a virtual DVD; it is a compressed file so that it doesn’t take so
long to download it from the Internet.
Once downloaded, you will have to expand the ISO file, also referred to as uncompressing it. Most any
file compression application today will work with ISO files but the most popular application for managing
ISO files is 7-Zip.
Below is a screenshot of the 7-Zip interface.
Note all of the ISO files that are shown. If you look at the drive path, you will see that all of these files are
located in the Downloads folder. To open an ISO file, simply double-click on it within the 7-Zip interface.
You will then be shown the contents of the file.
Once opened, you can extract the files to a designated folder on your computer so that you can access
these files at any time. Once extracted, simply click the setup.exe or installation file and install the
application.
For further information on working with ISO files go to
http://pcsupport.about.com/od/termsr/p/registrywindows.htm.
Administrative Users Versus Regular Users
All users are not created equal, and you want it that way. The last thing you want as an enterprise
administrator is to allow all users free reign of the operating system. You don’t want uneducated users to
delete vital system files or install unauthorized applications that may be riddled with malware and
spyware. You also don’t want them making configuration changes that will result in unexpected results
that may initiate a help desk call to undo the changes they made.
There are designated users who have administrative rights. These users have enhanced permissions and
have complete access to critical file locations of the Windows directory, designated tools such as
Computer Management, and the Windows registry. They also have permission to install application or
uninstall them.
Sometimes you may have been on a Windows 7 or Windows 8 computer and attempted to do something
such as install an application. You have then received a window prompt asking you for a username and
password. In this instance, you need to type in the credentials of someone who has an administrator
account. In order to have administrative rights, a user must be in the Administrators group.
Administrative rights have a cost however. Go to http://www.tomshardware.com/news/windows-windows7-uac-malware-malware,10054.html for the consequences of Administrative rights.