Windows XP. In July 37.2% of all desktop computers was running this nearly 12 year old operating system, while in August this dropped to 33.7%.
Break down the numbers on country level and the numbers and you find this.
In the U.S., for example, 16.4% of all personal computers ran Windows XP in July, or about one in six, Net Applications' data showed.
But in China, where XP remains king, 72.1% of the country's computers relied on the soon-to-retire operating system last month, or nearly three out of every four systems. In any XP doomsday scenario, that means China is in a position four times more precarious than the U.S.
If one assumes that recent trends in XP's decline continue, then its share in the U.S. will drop to between 9.1% and 11.1% by April 2014
So XP users are many in some countries, while others have updated to later versions.