“Hack your computer Sir?”

This is a very serious problem here in the UK (and abroad).

Remember, your Internet Service Provider (ISP) will NEVER call you about computer problems, it’s not in their remit.
Microsoft or other “technical support” teams won’t call you either (unless you have an on-going service contract).
Hang up on them, and ignore them.

If you have CallerID they often come through as a garbage numbers like “000000”. Just ignore it, or pick up your handset and then drop it back onto the hanger.

Don’t let them in!