For the event, Microsoft dressed up a cavernous former bus depot on a floating pier jutting from Manhattan into the Hudson River. Improvised siding shielded the roughly 500 reporters and other guests from the sight of a ruined pier to the south. This time, there were no rock stars in attendance.
This marks the first time that Microsoft has made touch-screen control the top priority, though the system can still be switched into the familiar desktop mode that allows for control by keyboard and mouse.
Users will notice a different greeting from Windows 8. Instead of seeing the traditional desktop icons, the system will show a mosaic of tiles displaying applications.
"Windows 8 shatters perceptions of what a PC now really is," CEO Steve Ballmer said.
Consumers can buy the upgrade starting on Friday, which will also be when the Microsoft Surface tablet goes on sale. In a separate presentation, Surface general manager Panos Panay dropped the tablet from shoulder height to the stage without breaking it to demonstrate the toughness of its glass and magnesium case.
Experts say Microsoft has a lot riding on the success of Windows 8. If it fails, it'll reinforce perceptions that the computer giant is lagging behind competitors like Apple or Google in an era of smartphones and tablets.
Microsoft reportedly planned to spend an estimated $1 billion just on its marketing campaign for the new system.
The Associated Press contributed to this report.