By default, when you click/tap on taskbar button for a program that has multiple tabs (ex: IE) or windows open in Windows 7 and 8, you will see thumbnail previews
of them to then be able to select one to make active.
This tutorial will show you how to enable or disable taskbar last active click
to be able to switch to the last active program window by clicking on the taskbar button in Windows 7
, and 8.1