Windows 1 - The year is 1985, and this is the first in a line of Microsoft multi-tasking graphical interfaces. International support arrived a year later, and support for the IBM PS/2 standard in 1987..
Windows 3.0 - The year is 1990, and Windows is starting to get quite polished, but..
Windows 3.1 - The year is 1992. This is the Windows version which popularized the Windows culture. Program Manager arrives, but it is all over by 1995. Installation is still executed over a DOS base.
Windows NT - The year is 1993 and Microsoft is building a parallel universe for power and business users. NT is not a shell running on a DOS base, and it will become the main basis for what is to come.
Windows 95/98/ME - The year is 1995, and Windows 95 introduces us to the first Start Menu. This was a real milestone. It was the first Windows which did not have to be installed over a DOS base. It was all done for you. Windows 98 and ME added features and functions, ME introducing us to 'System Restore'.
Windows 2000 - The year is 1999 and this OS was bolted down like a maximum security prison. It looked just like Windows 98 but that is where any likeness ended. However, it did have something of a rocky road trip and it saw four service packs during it's life.
Windows XP - The year is 2001. Microsoft combined W2K and ME to make this one. The Windows classic Start menu had continued through Windows 98. Millennium and Windows 2000 with little discernible change. Windows XP introduced us to the colourful world of 'Fisher-Price'. The harsh edges had gone, but at a price. XP was a very robust operating system, and did not need to be re-installed anything like as much as it's Windows 9x cousins. Unfortunately, it was way more memory intensive than it's Windows 9x cousins.
Vista - The year is 2006. It held on to XP's softer look with a very suave task bar and slick interface. We also got our first taste of Aero and UAC. It was and remains the best looking Windows UI of all time.
Windows 7 - The year is 2009, we still had Aero, but a generally flatter look. It is the first Windows version for years which did NOT an email client.
Windows 8 - The year is 2012 and the classic start menu is GONE !! Apps opened with tile icons are the order of the day for Microsoft, but are not accepted too well by home or business users. Windows 8.1 upgrade is released in 2013, and Windows 8.1 Update in 2014. Both make changes which might better appeal to the aforementioned users. Strangely, some prefer the original '8'.
Windows 10 - The year is 2015 - It's here..