Today, on November 20, 2010, Microsoft Windows turns 25 years old. On November, 20 1985, Microsoft released Windows 1.0, a 16-bit graphic user environment that was considered to be state-of-the-art at the time. In the two and a half decades that followed, Microsoft became one of the wealthiest companies in the world as Windows turned into the de facto operating system installed on over 90 percent of computers worldwide.

Windows 1.0 fit on just two double-sided floppy disks and needed 256K of RAM (512K if you wanted to run more than one program at a time). It wasn't until Windows 3.0 that the operating system really started to take off, but this is where it all began:

Here's a timeline for the releases of Microsoft Windows operating systems:

  • Windows 1.0: November 20, 1985
  • Windows 2.0: December 9, 1987
  • Windows 2.10: May 27, 1988
  • Windows 2.11: March 13, 1989
  • Windows 3.0: May 22, 1990
  • Windows 3.1: April 6, 1992
  • Windows for Workgroups 3.1: October 27, 1992
  • Windows NT 3.1: July 27, 1993
  • Windows for Workgroups 3.11: November 8, 1993
  • Windows NT 3.5: September 21, 1994
  • Windows NT 3.51: May 30, 1995
  • Windows 95: August 24, 1995
  • Windows NT 4.0: August 24, 1996
  • Windows 98: June 25, 1998
  • Windows 98 SE: May 5, 1999
  • Windows 2000: February 17, 2000
  • Windows Me: September 14, 2000
  • Windows 2000 Advanced/Datacenter Server Limited Edition: August 29, 2001
  • Windows XP: October 25, 2001
  • Windows XP Media Center Edition: October 31, 2002
  • Windows Server 2003: April 24, 2003
  • Windows XP Media Center Edition 2004: September 30, 2003
  • Windows XP Media Center Edition 2005: October 12, 2004
  • Windows XP Professional x64 Edition: April 25, 2005
  • Windows Fundamentals (for Legacy PCs): July 8, 2006
  • Windows Vista (for Business use): November 30, 2006
  • Windows Vista (for Home use): January 30, 2007
  • Windows Home Server: November 7, 2007
  • Windows Server 2008: February 27, 2008
  • Windows 7 and Windows Server 2008 R2: October 22, 2009

The software giant has managed to sell 240 million copies of the latest version of its client operating system, Windows 7. The company is just starting to push its new mobile operating system, Windows Phone 7, but the sales are nowhere near the same level.

Let us end by saying a "Happy Birthday!" to Microsoft. May the next 25 years of computing be just as exciting as the world goes mobile.