1) e-mails from 'Microsoft'
2) Unknown or known sources
3) Relying on anti-virus
4) Virus/Tojan/Spyware


1) e-mails from 'Microsoft'

Microsoft do not send out e-mails to computer users, unless replying to questions. If you receive an e-mail from '' then it could be one of the following:

i) a hoax virus alert asking you to delete system files which your machine actually uses (deleting such files may make your machine fail to start-up correctly!)

ii) a virus wanting you to run a file to make your machine get infected (see below).


2) e-mails from unknown or known sources

Virus files tend to infect other machines by having a program run and thus allowing the virus to perform its tasks. The most common file types which can be run as programs (plus possible viruses) end with the following: .exe, .com, .pif, .bat, .scr (not an exhaustive list as there may be others). You must also be awaire that files containing 'macros' can also be infected, which can include MS Word/Excel files (macros are small programs which run to automate tasks).

When receiving such files, you may notice them from people you don't know, which should automatically make you cautious. You should be just as cautious when receiving e-mails with attachments from people you know. The most commonly spread viruses are the 'mass e-mailing viruses' which send to all the people in the infected machines e-mail address book. The e-mails being sent often are disguised and look as if they have been sent from someone in the address book!

One way which can help stop viruses from being sent out from your PC if you do get infected with a virus is to put an e-mail contact as '!000' for their name and the same for their address. This will go to the front of the address book and will fail to be sent, if a virus tries to use this address to send to. This in turn can stop the flood of e-mails being sent by a virus, as it causes an error in the sending.


3) Relying on Anti-virus

Although anti-virus that runs 'live' is generally good at catching viruses, they cannot catch all threats. New viruses sometimes take a number of days until they can be detected and cleaned by anti-virus.

Norton seems to currently be the most used protection but still I have found installations with the newest up-dates still being infected with viruses. The problem is that due to Nortons popularity, most of the virus writers know how it works and sometimes try to disable or uninstall the software. Therefore even with anti-virus installed a little common sense still goes a long way.


4) Virus/Trojan/Spyware

Although viruses seem to currently cause the most problems with computer systems there can be other things which are not detected. Opening that e-mail attachment might enable other things to run, like Trojans and Spyware.

Trojans can be a little more potent then viruses as they often enable other users access to your PC and other interesting side affects..

Spyware on the face of it should not cause your PC any problems but this is not always the case. If you keep getting loads of pop-up screens, have gained an extra 'tool bar' in your internet explorer, or your home page keeps re-setting itself to one that you do not want - then you could have 'spyware' installed on your PC. The initial reason for this software was to make a note of which web sites you visited and sell on this directive advertising information. This software can cause your internet connection to be slower (or in some cases un-available) and allow other software to be run on your PC!

Please use the contact details if you believe you may be affected by anything mentioned above.