Extra ads on my browser screen
I have a Windows 7 setup and I am using Internet Explorer as my browser. Whenever I am surfing the net, a few ads appear on the top and bottom of the page which do not belong to that page. I dont click on them but still sometimes ads start popping up as separate windows. Why does this happen? How can I remove all this? I have used malware removal tool with Spy bot but it did not spot any defect. Please help.