CSC 110: Introduction to Computers
Learning Unit 1: Mini-Lecture
Computer Networks, Security, and System Maintenance
A network is defined as two or more computers connected via software and hardware in order to
communicate with each other.
The main function of a network is to facilitate information sharing. For example, let’s say you have a
personal account set up on the Indian Hills network. You log into a computer connected to the network
and save a file. You can then access that file from any of the computers connected to the network. You
don’t have to be at the same computer on which you created the file.
In contrast, your own personal computer is not connected to the Indian Hills network. So if you create
and save a file on your personal computer, you will not be able to access that file from a computer at
the college. You would need to save your file to a portable storage device, such as a flash drive or CD, in
order to access the file on another computer.
Security: Keeping Your Computer Safe from Hackers and Viruses
Now, let’s discuss how to keep the data on your computer safe. First, we’ll talk about hackers and
viruses. Then, we’ll discuss routine maintenance tasks that can help to keep your computer running
efficiently.
A hacker is someone who unlawfully breaks into a computer system, either an individual computer or
one that is part of a network. Some hackers view their illegal activities as a form of entertainment, like a
hobby, while others pose an even more serious threat, seeking to steal your identity or cause significant
damage to systems.
Hackers can gain access either by sitting at your computer and installing hacker software or (more likely)
by accessing your computer through an Internet connection. When you are connected to the Internet,
your computer is potentially open to hackers. Without the proper protection, it’s like leaving the front
door of your house open when you leave home.
Firewalls are software programs designed to keep computers safe from hackers. Firewalls close off open
ports through which hackers could potentially gain access to your computer. Be sure that your computer
has a firewall installed. Some operating systems, such as versions of Microsoft Windows, come with a
firewall. There are also companies that sell reliable firewall programs. The cost of these firewalls is
typically based on the level of security they provide.
A computer virus is a program that attaches itself to another computer program or file (known as the
host program) and attempts to spread to other computers when files are exchanged. Viruses can be
hard to detect, because they attempt to hide within the code of the host program.
What do computer viruses do? A computer virus tries to replicate itself on as many computers as
possible, which slows down networks. The effects of viruses range from annoying messages on the
computer screen to the total destruction of files on the hard drive. Virus creation is a form of cybercrime
because of its potential to destroy personal property.
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CSC 110: Introduction to Computers
Learning Unit 1: Mini-Lecture
How does a computer “catch” a virus? Computers can become infected with a virus in much the same
way that humans catch viruses – through sharing. Passing files back and forth via CDs or flash drives is
one way viruses are transferred. The embedding of viruses into email messages is probably the most
common way computers become infected. However, it’s important to clear up a common
misconception about this. Just opening an email message does not necessarily infect your computer.
Downloading or running a file that is attached to an email is generally how computers become infected.
Some malicious websites can also install viruses onto visitors’ computers that are unprotected. Two
basic rules to follow are:
1. Don’t download a file, if you don’t know from where or from whom it came.
2. Always scan files you download from websites, emails, flash drives, or other sources, with a
respected antivirus software program that has up-to-date definition files, before double-clicking
or using the file.
If your computer displays any of the following symptoms, this may be an indication that your computer
has a virus:
1. Existing program icons or files suddenly disappear.
2. Changes appear in your Internet browser. (For example, when you open your Internet browser,
a different homepage appears than the one you set, or you see new toolbars.)
3. Odd messages or images show on the screen.
4. Data files have become corrupt. (Keep in mind that there are many reasons files can become
corrupt. A virus is just one potential cause.)
5. Programs don’t work properly or crash (shut down unexpectedly). Again, this could be the result
of a virus or some other cause.
So, how can you reduce the chances of your computer catching a virus? The best defense against viruses
is to install antivirus software. These programs are specifically designed to detect viruses and take care
of them before they do any harm to your computer. There are several reputable companies that sell
antivirus software. There are even some reputable free ones. You can perform some research on the
Internet or (better in this case) ask a respected computer retailer for suggestions.
Once you have antivirus software installed on your computer, it’s important to run it and update it
regularly. A good guideline is to have the program perform a full virus scan of your entire system once a
week. A full virus scan can take some time, so you might want to set up the software to automatically
run the scan during a time when you know you won’t be using your computer. Also, ensure the software
regularly updates itself. It will download new virus definition files, which allow it to recognize and defeat
the latest virus threats.
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CSC 110: Introduction to Computers
Learning Unit 1: Mini-Lecture
Please be aware that antivirus programs can’t always fix a virus-infected file and make it usable again. If
your important files, such as papers you are writing for your courses or other critical information,
became infected by a virus and could not be salvaged, it could mean serious problems and stress for
you. So, be sure to keep backups of your files, either on CDs or flash drives, so you can restore them if a
virus damages the original files beyond repair.
System Maintenance
Finally, let’s talk about routine maintenance you can perform to help keep your computer running
smoothly.
1. Install Updates: Most programs and operating systems have an “install updates automatically”
feature that can be enabled in the Control Panel (usually available in the Start menu in
Windows). Take advantage of that feature. These updates often include security patches that fix
vulnerabilities that have been identified in your software.
2. Disk Cleanup: This is a system utility that allows you to remove files that can slow down your
computer, such as temporary files downloaded from the Internet.
3. Disk Defragmenter: Over time, as you add information to a file, pieces of the file are scattered
or “fragmented” in locations throughout your hard drive. When you open a file, it takes longer
for the computer to locate all the pieces of the file, making your operating system less efficient,
which slows things down. The disk defragmenter reassembles pieces of related files so that your
computer can function more efficiently. Think of it as a “Humpty Dumpty” utility – putting all the
pieces back together again.
Both the disk cleanup and disk defragmenter are system utilities that can be set to run automatically at
specific times. These utilities are found in the Start menu, under “Accessories” > “System Tools.” Please
note that running these utilities takes time, so you’ll want to run them when you won’t need to use your
computer right away.
Now you have a general understanding of how computers interact, how to protect your important files
from hackers and viruses, and how to perform standard system maintenance.
© Indian Hills Community College
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