Letter posted on the Internet:  

I have recently been receiving calls, allegedly from Windows Microsoft security, informing me my computer is in danger of crashing due to a plague of viruses, and if I open my computer they will eradicate said viruses via the phone. Is this a scam or genuine? SC, Didsbury Manchester, England. 

What is happening today: 

While many people are already aware of this racket, there are many more people in recent months who have been getting these hoax calls.

The scam always starts the same way: the phone rings at someone's home, and the caller asks for the householder, quoting their name and address before saying "I'm calling from Microsoft. We've had a report from your Internet service provider of serious virus problems from your computer."

They go on to warn that the computer will become unusable if the matter is not resolved. The puzzled householder is then directed to their computer, and asked to open a program called "Windows Event Viewer." Its contents are, to the average user, worrying as they look like a long list of errors, some labelled "critical." "Yes, that's it,"

says the caller. "Now let me guide you through the steps to fixing it."

The computer owner is directed to a website and told to download a program that hands over remote control of the computer, and the caller "installs" various "fixes" for the problem.  We wonder what they actually place on the computer. Then it's time to pay a fee: as much as $225 for a "subscription" to the "preventative service."  They take your credit card information and charge your account for $225.  Once they have your credit card information, they could charge other amounts at random. 

The caller asked if our client was a senior citizen.  When she replied yes, they gave her a 15 percent discount to make it appear legitimate.  Our client had to cancel the credit card, but was told she still had to pay the balance.  (This is now is dispute resolution)

Calls such as these prey on the fear that your computer will cease to function. They appear to target older or less technologically savvy householders. They are convincing, as they have a certain amount of your data, although they are using publicly available information and rely on the fact that (almost) everyone has a computer.

The best thing to do with these calls is to put the phone down. Alternatively, if you have time, fake an interest and then keep them occupied as long as you can. When you reveal that you have no interest in buying their services, they'll probably become annoyed, but while they are on the phone to you they won't be ripping off anyone else. Also, if you ask them for a phone number so you can call them back, they will hang up. 

It's worth noting that Microsoft says it will never contact a customer unless you have

registered a problem with it first.