According to stats from StatCounter, Windows 7 has overtaken Windows XP to become most used OS in this world. Windows XP which was launched by Microsoft almost a decade ago went on to become the most used OS in the history. When Windows 7 was launched in 2009, Windows XP had over 70% of the OS market share, but after that Windows 7 steadily increased its presence and replaced it to achieve this remarkable feat.
Thanks to Tom Warren for the heads up ! !