ARS Technica reports 20.87 percent of Windows users have made the switch to Microsoft's Windows 7 operating system.
Windows 7 has been steadily stealing share from Windows Vista and Windows XP ever since it was first released. It is now installed on one in five computers. Its predecessor Vista never managed to achieve that feat. In the 12 months since release, Microsoft sold 240 million licenses of Windows 7; by now that number is surely approaching 300 million.
Between January and December 2010, Windows XP fell almost 10 percentage points to 56.72 percent market share. In the same period, Windows Vista lost over five percentage points to 12.11 percent. Windows 7 meanwhile has gained over 13 percentage points, pushing it to 20.87 percent.