20 November 1985 may not mean much to the majority of the population, but it probably does to some of the people in Redmond. That was the day that Microsoft finally unveiled the first version of its Windows OS.
Of course, the company's first graphical operating system - which was basically just a GUI for DOS - didn't exactly set the world on fire. In fact, it was a bit of a flop, and failed to provide a compelling alternative to competing products from Apple and Digital Research, among others.
For $99 (about $195 in today's money), the first version of the OS came with a word processor called Write, a card file, a calendar, a clock, Reversi, a print spooler, RAM drivers and even old favourites Notepad and Paint. However, it lacked some of the more technical features of the competition - including the ability to overlap different windows - which resulted in limited commercial success.
Of course, Microsoft persevered - it was by no means a bedroom operation at this stage, having around 900 employees - and reaped the rewards with the very successful release of Windows 3.0 in 1990 and Windows 3.1 in 1992. And the rest is, of course, history.
Microsoft has certainly come a long way, transforming from plucky upstart going head-to-head with the big-boys of the industry to selling hundreds of millions of copies of Windows 7 and offering versions of the OS for desktops and notebooks, embedded systems, phones and servers. Seeing how much things have changed, we can't wait to see what the company can accomplish in its next 25 years.