Computer Virus Guide
This guide explains how you can easily avoid being infected by a virus.

Watch out for those emails

Your computer can become infected with a virus in two ways -

  1. By installing software programs from virus-infected CDs or memory sticks, or by downloading and installing virus-infected software from the Internet. In general, this can be easily avoided by only using software from reputable sources.
  2. By installing and running a virus-infected program received via email. This is the most common way for a virus to spread, but by following a few simple precautions, you can easily avoid being infected, even without the use of specialised virus protection software.

Email attachments are used to send legitimate documents and pictures with emails. These are usually shown by a paperclip symbol next to the received email. Unfortunately email attachments can also contain viruses. You cannot get a virus just by reading an email - you have to open the attachment. It is therefore important to be able to differentiate between harmless and malicious attachments.

Be cautious of any email with an attachment, even if it appears to be from someone you know. Virus-infected computers will often fake the sender's address, so an email appearing to come from your friend may actually contain a virus.

Check carefully the type of attachment the email contains. Your computer should display a warning box, asking you to confirm whether you want to open or save an attachment. To check an attachment, click once on the paperclip symbol in your email, then on the name of the attached file. A warning box will display the name of the attached file. Note carefully the ending of the filename (the last three letters, preceded by a dot). This is known as the file extension and determines the type of file that has been attached to your email.

these are common file types and may be opened safely
likely to contain viruses DO NOT OPEN
.doc Microsoft Word Document .scr Windows script file
.pdf Adobe Acrobat portable document file .exe Executable file
.xls Microsoft Excel spreadsheet .pif Windows script file
.txt Plain text file .bat Windows batch file
.jpg Picture or photograph There are many other file extensions
you may come across, but the ones above
are the most likely to contain viruses.
.gif Picture or photograph
.htm Website page
.eml A forwarded email file. This is safe to open,
but within itself may contain further attachments.

Please note: some virus file names may have a double extension, e.g. snowhite.doc.scr It is the last three letters that count ! In this case the virus creator is trying to fool you into thinking this file is a harmless word document but in actual fact it is a Windows script file containing a virus. Others may use a lot of blank spaces in order to hide the real file extension e.g. invoice.txt                                  .scr

If you are not sure about what type of attachment it is, do not open it. Delete the whole email. If you think it may be genuine, confirm with the sender that they did indeed send you the email before opening the attachment.

Virus Hoaxes

These are very common. You will receive a harmless email, warning you that a new virus has been found. This email may be from someone you know and it will ask you to forward the warning to everyone else. Sometimes it may also ask you to delete a file from your computer which it claims is infected. This type of message is a HOAX. Almost certainly there is no such virus and the hoax perpetrators are merely trying to cause confusion and panic people into thinking they have been infected. Do NOT forward this message to anyone and do NOT delete any files from your computer !

As a rule, any email that asks you to forward it to everyone you know, it is very likely a scam of some kind, a chain letter or an advertising stunt. Ignore it and DO NOT forward it to anyone.

If you forward a hoax warning to everyone in your contacts list you will be:

  • Causing un-necessary concern
  • Clogging up other people's mail boxes with junk
  • Giving away all the email addresses in your contacts list for everyone to see

You may also find your email address black-listed by your internet service provider as a source of spam !

Please visit our page on email security and spam for more information and helpful hints.

Google is your friend !

The simplest, easiest and quickest way to check if an email you have received is a hoax or contains a virus is to go to Google and type the subject heading of your email into the search box. You will quickly discover that there are thousands of others affected by the same problem.

To check if a virus warning is a hoax you can also visit one of these sites: or

Anti-Virus Software

If you are a Microsoft Windows user, we strongly recommend that you use the Microsoft Security Essentials anti-virus software. This is the official Microsoft product and is specifically designed to be used with Windows XP, Vista and Windows 7. You can download this FREE from the Microsoft website. Once you install it, you will not need any other anti-virus software.

Go to

You may, if you wish, use anti-virus software from one of the many commercial vendors, like Norton, McAfee, Symantec etc. but be aware that some of these programs may slow down your computer.

What to do if you think you are infected with a virus

If you suspect you have already been infected with a virus, DO NOT start your email program - not even to read incoming emails. Many viruses can spread by sending copies of themselves to recipients from your address book without you knowing !

You can use Internet Explorer to visit the Microsoft Security Essentials website and download the anti-virus software. If you already have this installed, use it to run a scan of your computer. The website will also give help and support in removing viruses. DO NOT restart your email until you are sure your computer is free of viruses.

BHDTA website reference section

The reference section on our website contains much valuable information, not just about carriage driving.

  • COMPUTER VIRUSES - find out how to easily avoid viruses and virus hoaxes
  • EMAIL and SPAM - Make your emails more reliable, protect your email address and reduce the amount of junk
  • ON-LINE SALES SCAM - make sure you don't lose your money or goods to fraudulent dealers
  • DOWNLOADING FILES - how to download and print out files and forms.