Windows, which represents over 10% of Microsoft's revenue even as the company has grown by selling cloud services, became more critical during the pandemic as people stayed home and spent more time with Windows 10 for school, work and gaming. The announcement comes almost six years after the introduction of Windows 10, which is the world's most widely used PC operating system, with over 1.3 billion devices using it. Microsoft revealed Windows 11 during an online event on Thursday.