This guide is intended for home computer users who have little or no experience with computer security.
Virus infections can be prevented by taking specific steps during setup and by avoiding specific actions during use.
Start with a minimal amount of software from reputable companies
Windows 7 is an operating system that comes with most new home computers. It includes a firewall and automatically updates itself. It also warns you when you act in a way that can expose your computer to a virus. Security Essentials is a free antivirus program that you can download directly from Microsoft by following the link above. It automatically updates itself, does not interfere with your use of the computer, and rarely requires your attention.
Chrome is a web browser that automatically updates itself and offers significant protection against malicious web pages that try to infect your computer with viruses. Chrome also includes Flash and a PDF reader and automatically updates both. You don’t need to download or update Adobe Flash Player or Adobe Reader yourself.
Carefully consider any additional software you plan to install
Each piece of software you install could include a virus or a flaw that could allow a virus to infect your computer. Do not install software on your computer unless all of the following are true.
1. You need the software to accomplish a task. Consider online services such as those mentioned below as alternatives to software that must be installed on your computer. Avoid software that claims to protect, clean, or maintain your computer. Windows 7 and Security Essentials provide all of the tools necessary to protect and maintain your computer and they work without attention from you.
2. You can accurately evaluate the quality of the software and the reputation of the company that produces it. If you can’t confidently state that a piece of software is of high quality and that it is produced by a reputable company, do not install it on your computer.
3. You acquired the software from a legitimate source. If you downloaded a piece of software from a website other than that of the company that produced it, you cannot be sure that the software is authentic and free of viruses. The same is true of software from a CD that is obviously homemade. Do not install software that you receive from other individuals. You are trusting not only the person’s intentions but also the individual’s technical skills.
Create a Standard User account for each person who will use the computer
Create an account for each person who will use the computer. Choose the Standard User type rather than the Administrator type for each account. Create a Standard User account for yourself even if you are the only person who will use the computer.
A Standard User cannot make most changes that affect other users. If a Standard User runs a file that contains a virus it is likely that only that user’s account will be affected. Use the Administrator account only to make changes to the computer such as to install software or create accounts.
Use webmail instead of an email program that runs on your computer
Accessing your email through a web browser keeps emails with viruses off your computer. Most services will scan attachments for known viruses and notify you before you download them. If you use an online office suit (see the next topic) you can avoid downloading many attachments at all.
All major internet service providers offer the option of using email through a web browser. Google, Microsoft, and many others offer free web based email accounts that you can keep if you switch to a new internet service provider.
Use a web based office suite instead of one that runs on your computer
Both Microsoft and Google offer free online office suites. Using an online office suite instead of Microsoft Office keeps documents with viruses off your computer. Since the services store your documents online you can recover them from another computer if yours breaks.
Avoid actions that could expose your computer to viruses
No virus scanner or other security software can provide absolute protection against all viruses. You must avoid actions that expose your computer to viruses. Chrome and Windows 7 warn you when you take actions that could result in a virus infection. You are given the opportunity to cancel the action. You can protect your computer by responding to each warning by canceling the action.
When you download a file that could contain a virus, Chrome displays a warning, “This type of file can harm your computer. Are you sure you want to download…?” You are then given an opportunity to cancel the download and protect your computer. If you download the file anyway you expose your computer to whatever viruses might accompany your download. Using web based email and a web based office suite will reduce or eliminate your need to download files.
When a website asks to install an extension that could contain a virus, Chrome asks you if you would like to install it. Your computer will be protected if you ignore or close the warning. If you install the extension you expose your computer to whatever viruses might accompany it.
When you run a file that could contain a virus Windows 7 warns you and gives you the opportunity to cancel the action. The same caveat as above applies if you proceed. Viruses can be stored on CDs and USB keys as well as included with downloads. Do not assume that it is safe to run a file merely because it was not downloaded from the internet.