My antivirus gave me an error while surfing the internet the other day. Afterwards my IE homepage was changes as well as my default search engine, and a tool bar added to IE. The toolbar and search engine was ask.com. I uninstalled the toolbar and fixed my homepage and search engine, but now about three times a day a IE window pops up and shows an advertisement. It usually says media.fastclick.... and then goes to another page. I have ran a few spyware programs and nothing is being reported. I have tried windows defender, and LopSD. I have attached a hijackthis log. What should be my next step?