I got quite a few of these calls but 'smelled a rat' immediately and told them to "sod-off".

Then one rainy day I was a bit bored and decided to have a bit of fun. I pretended that I had computer problems and would welcome their help. The person on the other end of the phone asked if my computer was booted up - and I told her that it was. She then began to issue me with instructions - which I pretended to follow. At some point she asked me what I could see on the screen and I said that I could see a duck. I then accused her of "programming a duck into my computer"!

She told me that my computer must be "heavily infected with viruses" and that she would have to get her supervisor. Things then got completely surreal because the supervisor was obviously slavishly following a script, didn't appear to hear my increasingly hysterical ravings about ducks, and kept on calmly issuing instructions!

In the end I got bored and told her that I didn't believe that she worked for Microsoft and that she should "sod off" ...