If it's not people trying the fool you into a webpage that pretends to "scan" your computer for virus and find 100 Cirtical Objects that need removing through their software , only after the unknowing user installs the software they are constantly harrased by popups!
It's people from India calling you up after getting your name and number out of the telephone directory and pretending to be your ISP or Microsoft saying you have issues on your machine that they will need to fix.
A site F1Compstepuk.com ( Now shutdown by HostGator ) which charged you £185 after install teamviewer so the person could remotely access your machine "and remove the virus'" which had been causing your computer slowness and even 404 Errors!
From Microsoft's Own Website
"Microsoft does not make unsolicited phone calls to help you fix your computer
In this scam cybercriminals call you and claim to be from Microsoft Tech Support. They offer to help solve your computer problems. Once the crooks have gained your trust, they attempt to steal from you and damage your computer with malware including viruses and spyware.
Although law enforcement can trace phone numbers, perpetrators often use pay phones, disposable cellular phones, or stolen cellular phone numbers. It's better to avoid being conned rather than try to repair damage afterwards.
Treat all unsolicited phone calls with skepticism. Do not provide any personal information."
So guys, make sure you recognise the number and you know the person logging in remotely to your machine!