Hello, is my computer infected if I receive these strange pop-ups “Pc.avdesktop.com says…” ? These alerts say my computer is at risk, and so on, and blahblahblah. They say I need to fix my computer, but for some reason i cannot do it myself so I need to call some microsoft technicians. I think these warnings are fake, but how do I know where do they come from? How can I stop them?