1.Windows 1

Source: Wikipedia.com (https://en.wikipedia.org/wiki/Windows_1.0x)

2.Windows 2.1

Source: Wikipedia.com (https://en.wikipedia.org/wiki/Windows_2.1x)

3. Windows Vista

Source: Tom Warren, 2013, Theverge.com (https://www.theverge.com/2013/8/23/4651678/ballmers-biggest-regret-windows-vista)

4.Windows 7

Source: Wikipedia.com (https://en.wikipedia.org/wiki/Windows_7)

5.Windows 10

Source: Tom Warren, 2015, Theverge.com (https://www.theverge.com/2015/7/28/9045331/microsoft-windows-10-review)