In the tutorial I tell you to go use IObit Uninstaller 4 to look under the “Toolbars & Plug-ins” tab to see if anything is there. What you can also do is look in the “Programs” category tab to see if Ask.com or any other toolbar is mentioned there.
Don’t just look for “Ask.com”, look for anything that looks suspicious. Something you know you didn’t install. It may be hiding under a different name.