Can you explain why my computer keeps sending web pop-up messages saying that my computer possibly has Trojans? It was working properly all the time. I also never click on suspicious links and I do practise safe browsing manners. What is the problem here? This annoying ad by Adsystemscan.com claims that it has scanned my computer and found a lot of malicious programs on it. I believe that is nonsense. Please help me to solve this computer issue. By the way, the pop-up warning is almost impossible to close.