Protect your computer

Types of threats

For you to be capable of protecting your computer, you first need to be aware of the basic threats against your computer. There are a multitude of different threats out there. They spread primarily through the Internet (when you download things) or when connecting new hardware to your computer (like a USB flash drive).

Below are four of the most basic threats defined for you.


A virus is a computer program that attaches itself to existing programs to replicate itself and spread from one computer to another. It typically slows your computer down and causes your computer to behave strangely (like opening the wrong applications or deleting existing documents and files). Viruses can lead to your computer becoming so slow and "broken" that it is unusable.


A worm is a standalone computer program that replicates itself to spread to other computers (just like a virus) through a network (like the Internet). Unlike viruses, worms do not need to attach itself to existing programs. Worms normally consumes bandwidth on a network. That means it makes the connection between the computers on the network so slow, that it is unusable.

Trojan Horses

A Trojan horse is a non-self-replicating program that appears to be performing a desirable function (like speeding up your system), but instead leaves a backdoor open allowing unauthorized access to your computer. That means that an attacker may be able to access all the personal files and applications on your computer. The attacker therefore has full control of your computer!


Spyware is software that helps attackers gather information about you, without you even knowing about it. Spyware can be very dangerous. There are spyware called Keyloggers which can see everything that you type on your keyboard. That means that they can see when you enter your password and monitor exactly what you are doing at all times.

Types of protection

At a minimum, every computer should run an anti-virus and firewall. These types of software help to identify any type of malicious programs (like the ones discussed above) and prevent your computer from becoming infected.

It is very important that you only have one anti-virus and one firewall program installed on your computer. Having more than one of either does not mean that you are more protected. On the contrary, it may cause problems and eventually make your computer more susceptible to becoming infected. So, if you already have an anti-virus on your computer and want to install a new one, first uninstall the old one before installing the new one.

Below is a very good and respectable anti-virus and firewall program. If you are running Microsoft Windows 7 or later, you don't really need an additional firewall program, since Windows Firewall (along with Windows defender) is a really good built in firewall. Nevertheless, you should still install an anti-virus program.

Avast logo

Avast Anti-Virus

Anti-virus software is used to prevent, detect and remove computer threats (like the ones mentioned above). Since viruses can come from many sources, like the Internet or a USB flash drive, the Anti-virus program has to continuously monitor your computer while you work. When a threat (like say... a virus) is detected it removes it from your computer. Anti-viruses need to be continuously updated to be able to identify all the new viruses that are created every minute.

Follow this link to download Avast for free:

Download Avast Anti-Virus
Zonealarm logo

ZoneAlarm Firewall

A firewall is software that protects your computer from harmful attacks (like the ones mentioned above) that try to access your computer through a network (like the Internet). Firewalls works by looking at all incoming "signals" that your computer may receive. If the firewall finds anyone of those "signals" suspicious, it will not allow it through to your computer. It can be seen as a barrier between you and the outside world that protects your computer from any harm. It's almost like an overprotected parent.

Follow this link to download ZoneAlarm for free:

Download ZoneAlarm Firewall

Diagram of how the Internet works

Diagram of how the Internet works

As you can see in the diagram above, there is a link between all computers via the Internet.

This means that a hacker can send a virus to your computer through the Internet! Luckily, there is a firewall between your computer and the Internet which will stop the virus in its tracks.

If the virus does manage to get through the firewall, the anti-virus installed on your computer will delete the virus, keeping your computer healthy!