Microsoft launches its first Windows 10 tablet at $899

"We're moving people from needing to choosing to loving Windows, and these devices promise to fuel even more enthusiasm and opportunity for the entire Windows ecosystem," Chief Executive Satya Nadella said at the event.

Microsoft also said its new tablet will come with Windows Hello, an automatic biometric sign-in option introduced earlier this year. The feature allows users to scan their face, iris or fingerprints to verify their identity and give them access to Windows phones, laptops and personal computers.

Microsoft also introduced a Surface Pen, which has year-long battery life, 1,024 pressure points and comes in five colors with inter-changeable pen tips.

Even as Microsoft has positioned the Surface as a laptop replacement, it's making a separate Surface laptop model, the Surface Book. Microsoft says it's for scientists, engineers and gamers who need a lot more performance than a tablet.

The laptop starts at USD 1,499, compared with USD 899 for the new Surface Pro 4 tablet. And while the Surface Book is called a laptop, the screen is detachable so that it effectively becomes a tablet. The company touted its clipboard-like functions for people on the go.

The Surface Pro 4 tablet is faster and thinner than before, yet it comes with a slightly larger screen at 12.3 inches.

The Surface Book and Surface Pro 4 are the first Surface devices to ship with Windows 10 already installed, though older models are able to get free upgrades.

Although the Surface still represents a small part of Microsoft's overall business, it provides a window into the company's various ad-supported services, including search and maps.