Some Windows 8 PCs will be hybrids that look like laptops, but also have detachable display screens containing a separate battery so they can work like tablets, too.
Those devices will face direct competition from Microsoft's Surface.
On Thursday, Microsoft also spent time touting the Surface as a more versatile and durable alternative to the iPad, still the most popular tablet on the market.
At one point, a Microsoft executive dropped the Surface on the stage floor to demonstrate how difficult it is to break.
In another gimmick, a different Microsoft executive stood on a Surface with wheels to show it even had the strength of a skateboard.
The Surface goes on sale Friday, priced at $499 for a Wi-Fi-only tablet with 32 gigabytes of storage. Apple charges the same price for its latest full-size iPad with half the storage capacity.
The price for a separate Microsoft "touch cover" that also serves as an attachable keyboard starts at $120.
Image: A person tries a Samsung tablet computer running Windows 8 at the launch of Microsoft Windows 8.