The people who ring with the "problem with windows" are not selling anything; they are trying to get into your computer. I did read about someone who told them they should be ashamed of themselves and was told to eff off. I don't see any need to be polite to people who are trying to scam the vulnerable.
Found out today, can't take it in
Well, that was a farce.........


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after your suggestions Experigran mine seem tame. Leave the call open and carry on with your day to day business (as long as it is not too revealing) they soon ring off; or use a whistle. 
