I have a colleague who is having an issue with popups, i.e., spam popups or advertisement windows continually appearing in her browsers (IE, Firefox and Chrome). She is using a PC. She has the pop-up blocker activated in her browsers, but says that doesn't seem to be helping much. She also stated that she has Norton AntiVirus software installed on her computer and did a full system scan. The scan revealed that 37 tracking cookies have been resolved but the situation hasn't changed.
What should I advise her to do?