I do a lot of school work online, and I use multiple pages to do my work. 9 times out of 10, I can see pop-up ads on the blank space of every web page I visit. It takes me long time to load a web page. And sometimes, it pops up ads when I move the mouse over some highlighted words. I tried many virus scans but could not detect anything. I don't know what's wrong with my computer. What can I do to fix this problem?
Thanks in advance!