Oh NOES the WWW says my computer is infected!

Gosh, I have heard of these people, but I've just never been phoned by one before. This is posted here as a public service, because while I'm computer savvy and would never fall for it, other people might not be that lucky.

Phone rings. I pick up. Silence. After a few seconds of saying "helloooo?", this is what happens:

Caller with a heavy [Indian] accent: Hello is this Mrs T(doesn't sound like my surname, but maybe he can't pronounce it properly, which wouldn't be the first time)?
Me: Err ... (did it sound remotely like my surname or not? I decide it didn't) ... no ...? ... It isn't? (expecting a "sorry, wrong number")
Caller: Can I please speak to the person who owns this telephone number?
Me: ...Speaking? (smelling a cold caller, despite our number being unlisted)
Caller: Hello, I'm calling from World Wide Web and we have detected that there's a problem with your computer.
Me: ... Riiiight ... Try the other one? I've worked in tech support.
Caller: Blah blah blah your computer is at risk blah blah.
Me: No, it certainly ISN'T, and I'm not buying anything of what you're saying. Don't bother phoning this number again.
(This is where the caller hung up on me.)

Having random people phone you up to say that there's a problem with your computer is a WELL-KNOWN FRAUD! ANYONE who phones you up out of the blue to say your computer has a problem is trying to SCAM YOU in one way or another, whether it be for your money or personal data.

If your computer has a genuine issue, you will NEVER EVER receive a phone call from a legitimate company about it. Not Microsoft, not Apple, not even your ISP. It doesn't matter if they've actually got your name right, they're FRAUDSTERS. Tell them to sod off, and don't be polite about it.

If you aren't a "computer person", which means you're sadly more likely to fall for this scam, and you're worried about your computer, you get in touch with a friend or family member who does know about computers and ask them about it.

NEVER TRUST A PHONE CALL FROM SOMEONE YOU DON'T KNOW WHO SAYS YOUR COMPUTER HAS A PROBLEM!

There are ways they can get your phone number - or it might just have been picked at random by a number generator. There are even ways they can have the correct name attached to that phone number.

If they say they're phoning from a recognised, big-brand company like Microsoft or your ISP, take the person's name and number and say you'll phone them back. A legitimate business won't have an issue with that request. Look for a customer service number on the real company's website, e.g. if you got a call from "Virgin Media", go to the Virgin Media website and look for the customer service number. Phone that number, not one the person might have given you (if they do give you a number, you can always google it to see what comes up).

Tell the company you allegedly got a cold call from that [name] called about your computer and you want to make sure it was actually that company phoning you for real. Odds are, it wasn't. This is also good practice if someone claiming to be from your bank's fraud department phones you to say there are suspicious transactions on your account. (Again, your bank's fraud department will understand if you want to make sure they are who they say they are.)

Don't just take a stranger's word for it and hand over your details, because you'll be handing your personal details and/or money over to fraudsters / scammers / criminals.