Prevent Internet Explorer tabs from opening tabs in stack in taskbar
Solution 1:
See "How to Disable IE8/IE9 Tab previews in Windows 7 taskbar"
To disable IE tab previews in taskbar, just open Internet Explorer > Tools > Internet Options. Open settings for ‘Tabs’ and uncheck the box saying ‘Show previews for individual tabs in the taskbar’. Click Ok and restart IE for letting changes to take effect.
(The Tabs settings are opened via a button in the General tab of Internet Options)
This solution works for Internet Explorer versions 8 through 11.