Trading Standards are warning people in Cheshire West and Chester to be on their guard against computer fraudsters.
The service has received reports of unsolicited phone calls from people purporting to be from Microsoft claiming there is a serious problem with their computer.
The householder is urged to download a programme to get rid of the "virus" and is asked for personal information and bank account details.
Investigations manager Vanessa Griffiths said: “These scammers are acting with the intention of stealing money and personal information.
“We strongly advise anyone receiving a call of this nature to hang up the phone.
“Unfortunately, fraudsters are always thinking up new ideas of separating people from their hard-earned cash.
“Our advice is to never give personal information or bank account or credit card details over the phone.”
Microsoft states on its website it does not make unsolicited phone calls to fix computers or to request personal details.
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