Microsoft howed off its upgraded operating system, Windows 8, at an event in New York on Thursday.
The new operating system is designed for a touch-friendly interface and is built to function on both PCs and tablets.
"Windows 8 is a major milestone in the evolution and revolution of computing," said Steven Sinofsky, president of Windows and Windows Live Division.
The new OS is available for purchase on Friday, and another version for smartphones will be available next week. While it's still unclear how consumers will respond to the dramatically different interface of Microsoft's new OS, CEO Steve Ballmer said people will love the new Windows system and the devices that run it. (Read More: Here's Why Surface Beats Apple's iPad: Ballmer )
"Windows 8 shatters perceptions of what a PC now really is," Ballmer said. "We've truly reimagined Windows and kicked off a new era of Microsoft and for our customers."
The upgrade is designed to allow devices to have a faster boot time and use less memory. It's also designed to work with a mouse as well as touch.
Sinofsky also announced the grand opening of the Windows online store where it will sell applications and media content, much like Apple's iTunes store does. The store will run in 231 markets and in 109 languages. While Sinofsky acknowledged that the Windows Store may not have as many apps as other app stores, he said that hundreds of apps are being added everyday.
Microsoft also showed off its Surface tablet, which runs on Windows 8, at the event. The mobile device hits store shelves Friday and is priced at $599 with the touch keyboard cover.
The Surface features a camera on the front and back, comes installed with the Office software, and will run Windows RT, a version of Windows 8.
"Windows 8 PCs really are the best PCs ever," Ballmer said. "Windows 8 really does bring together the best of the world. PC, tablet, work and play."
The launch of the Surface tablet is the latest in a series of new tablets over the last several months. Google introduced its new Nexus 7 during the summer. Amazon's Kindle Fire HD was unveiled in August and Apple just took the veil off its iPad mini Tuesday along with its fourth generation iPad.