Froze up my computer

I suddenly received a notice on my screen that my computer had been infected with pornographic software containing a virus that would infect my computer, call 1-855-399-0154 to repair my computer.  They told me that their company was headquartered in Salmon Idaho and that they were an authorized Microsoft repair service.  fter accusing the of all sorts of mischief, I still could not use my computer.  On the advice of Geek Squad, I rebooted.  All was OK.