The problem is virus writers are a highly motivated group of people who constantly develop new and enticing ways of making you spread their virus.

"What sort of virus scanner do you have?"

"I don't know it came with the PC I think..."

"Does it update itself with all the latest virus definitions automatically?"

"I seriously doubt it. Is that a problem?"

"Well about 30 new viruses are released "into the wild" every week. If your scanner doesn't know about them then it probably won't catch them."

"Oh ... oh dear."

Viruses can be extremely damaging, time-consuming, expensive and aggravating and newer cleverer ones spring up all the time.

Viruses like Sircam can be particularly damaging as you could find your private and confidential documents being mailed round to all of your address book contacts.

It also means that you may well receive a virus from a close friend or colleague and statistics show that in the main we have few qualms about opening attachments from people that we know.

Subject lines can be different every time which makes it more difficult to spot and means that an email containing a virus will not be immediately obvious to even the most experienced user.

The virus writers are always one step ahead of the anti-virus software industry and so users need to be expecially vigilant to the new strain of viruses currently emerging. Up to date anti-virus software is a good start but effective protection against viruses and worms requires a much more proactive approach.