In Windows 8.1 there are two versions of Internet Explorer 11, one that is the desktop-mode IE and the other being the modern-style IE. I get asked why there are two versions all the time, and I honestly have no idea. I use the desktop mode all the time and this is how you can force it to switch to the desktop mode.
The easy way is to have more than one browser installed as IE then sulks and only displays in desktop-mode.
Alternatively, to change IE’s setting, just go to the Windows 8.1 Start Screen and click on the Search option. Type “Internet Options”. In the displayed results click on Internet Options to open the Internet Properties panel. Once in Internet Properties, click on the Programs tab and you will see the Opening Internet Explorer section at the top. Click on the dropdown selector and choose Always in Internet Explorer on the desktop, and tick the checkbox next to Open Internet Explorer tiles on the desktop then click on OK.
Behold, no more shuffling around the different IE modes in Windows 8.1.