In Pictures: Windows into history

November 1985: Windows 1.0 launches, after four years in development as “Interface Manager”. For PC users, it was one of the first means to execute commands without typing them in directly, and to carry out more than one task at a time

December 1987: Windows 2.0 debuts and over the following year becomes Windows/286 and Windows/386. The release introduced icons, the possibility of overlapping windows, and venerable word processor Word and spreadsheet program Excel.

May 1990: Windows 3.0 was a major visual overhaul to the operating system. It marked the beginning of Windows’ rise from obscurity to ubiquity, presenting a credible threat to operating systems from Apple and Commodore.

October 1992: Windows 3.1 claimed some 1000 changes over Windows 3.0; most notable was the “drag and drop” functionality within File Manager (to later become Windows Explorer) and context-sensitive help.

August 1995: Windows 95 was again a big visual change and later versions included Internet Explorer for the first time. It was the first blockbuster operating system, selling 40 million copies in the first year after its release.

June 1998: Windows 98 presented primarily behind-the-scenes improvements. In a press demonstration of improved “plug-and-play” hardware installation capability at the OS’s launch, the system famously crashed, resulting in the "Blue Screen of Death".

September 2000: Windows ME (Millennium Edition) incorporated a number of changes first seen in Windows 2000, which was released primarily for business users. Introduced “automatic updates” to the OS as well as “System Restore”.

October 2001: Windows XP was the first consumer-focused Windows release to be built on architecture from its business-oriented Windows NT systems, and the first to verify authenticity through “product activation”.

November 2006: Windows Vista included a raft of visual changes, but behind the scenes, the release focused on security. However, many derided its restrictive licensing, integration with third-party applications, and digital rights management.

October 2009: Windows 7 sees further integration into a home network and more of the “Aero” visual effects that both started with Vista, along with support for multi-touch on touchpads and touchscreen devices.