Imagine a world without the Start button. No, I'm not talking about Windows 8. Dig deep into your memory, and you may recall a time when Windows 3.1 ruled the Earth.

Twenty-five years ago this month, Microsoft released version 3.1 of its MS-DOS graphical-shell-turned-operating-system. Windows 3.1 became the first version of Windows to be widely distributed with new PCs, cementing the dominance of Microsoft's OS on the IBM PC platform and signaling the dawn of the Golden Age of Windows.

In honor of this anniversary, let's take a visual tour through Windows 3.1. In the following slides, I'll highlight many of the innovations this colorful GUI brought to Windows for the first time.