Four months after pitching Windows 10 to businesses, Microsoft is focusing on consumers at an event where CEO Satya Nadella and other officials are pledging that the new OS offers individuals significant advances over Windows 8, its problematic predecessor.

“Today is a monumental day for Windows,” Terry Myerson, executive vice president of the Operating Systems group, said at Wednesday’s event, being held at Microsoft’s Redmond, Washington, headquarters and available vialive webcast.

The first big news: Windows 10 will be offered as a free upgrade to current users of Windows 8.1, Windows Phone 8.1 and Windows 7 during its first year of availability.

However, Myerson said “this so much more than a free one-time upgrade.” Once installed, Windows 10 will be kept continually “current” throughout the lifecycle of the device. As the OS is treated more as an Internet service, asking what version of the OS someone has installed becomes irrelevant, he said.

As Microsoft has stated previously, Myerson reiterated that, unlike previous iterations of the OS, Windows 10 will deliver a consistent yet tailored product family across all types of computing devices, from screenless, embedded IoT sensors to all-in-one computers with gigantic displays. The Windows 10 family will also include versions for smartphones, tablets, wearables, hybrid tablet-laptops, TVs, PCs and the Xbox gaming console.

For developers, there will be a common development platform, whether they’re building enterprise software or games, and a single application store to purchase, distribute and update the apps.

Joe Belfiore, the vice president of the Operating Systems Group at Microsoft, followed Myerson on stage, and showed the Cortana voice-activated digital assistant working for the first time on a Windows 10 PC, using a pre-release build of the OS that will be released to testers in the coming months.

There are currently about 1.7 million [m] people signed up with the Insider program to test Windows 10 before it ships commercially, which is expected to happen by mid-year.

Since the release of Windows 8 in 2012, Microsoft has been in a persistent damage-control mode regarding the OS, so it’s hoping to turn over a new leaf with Windows 10 and close the chapter on its predecessor. With Windows 8, Microsoft misread the market and botched the product’s user interface, leaving a trail of many unhappy customers.

Windows 8 horrified critics with its radically different default Modern UI, which was optimized for touchscreen tablets, and with its alternate traditional desktop, which was included to run legacy Windows 7 applications but lacked key familiar features like the Start button and menu.

Users also complained that the process of toggling between the Modern interface and the traditional desktop was clunky and erratic. Microsoft addressed some of the biggest complaints in Windows 8.1 and Windows 8.1 Update, but it never fully fixed the problem.

To drive the point home that it has listened to the criticism, Microsoft decided to skip a number for the next major edition of Windows, jumping from Windows 8 to Windows 10, which the company has described as “a whole new generation” of the OS that delivers what consumers and enterprises “demand and what we will deliver.”