The new software will let Android apps run on the Windows desktop.
Product manager Panos Panay promised smaller, faster security updates - a common complaint for Windows users - and said they would happen in the background.
Windows 11 will also let users configure multiple desktops for work, home, and gaming, like on a Mac.
Microsoft says there are currently about 1.3 billion devices running Windows 10.
An early preview version of the new system will be released for app developers next week.