Fourteen months after Microsoft released Windows 10, its "last" Windows version ever, the company said the new operating system is now running on more than 400 million devices around the world. That's an increase of more than 50 million since Microsoft last updated its usage figures earlier this year.

Calling the OS "the most secure Windows," Yusuf Mehdi, corporate vice president of Microsoft's Windows and Devices Group, said on Monday that enterprises are moving faster than ever to adopt Windows 10. Unlike past iterations of the operating system, future updates to Windows 10 will be rolled out automatically via the cloud, rather than as discrete and separate versions.

Mehdi added that new features announced Monday at Microsoft's enterprise Relevant Products/Services-focus Ignite conference will provide even stronger security for Windows 10 users.

Those updates include Secure Productive Enterprise and a new Enterprise Mobility + Security E5 suite, both of which will be available starting Saturday. Among the other new enterprise offerings arriving soon are Windows Server 2016 and System Center 2016, both of which are due for release in October.

Adoption Rates 150% Faster than for Windows 7

The adoption rate for Windows 10 is running 150 percent faster than that for Windows 7, Mehdi said during the opening session of the Ignite conference in Atlanta Monday. He cited the security of the new operating system as a big reason that large organizations, such as the U.S. Department of Defense, are adopting Windows 10.

"[T]he work that they've done to push forward to get to over 4 million devices planned over the next year is pretty incredible across all branches of the military," Mehdi said.

Other organizations that have adopted Windows 10 include Land O'Lakes, Expedia, Kimberly Clark and Union Bank & Trust, Mehdi said in a blog post Monday,.

The latest updates to Windows 10 will make security "even stronger," Mehdi said. Windows Defender Application Guard, "makes Microsoft Edge the most secure browser in the enterprise," he said in the blog post. By expanding its Advanced Threat Protection technology across Windows 10 Enterprise and Office 365, Microsoft is introducing "complete protection across endpoints and in the cloud."

Ongoing Updates Target Reliability Issues

Despite Microsoft's assurances about Windows 10, not everyone is happy with the new operating system, which Microsoft recently began updating with the rollout of the Windows 10 Anniversary Update. Ongoing complaints have emerged regarding compatibility and reliability issues, which is likely to explain why Microsoft is phasing in the anniversary update over a period of three months so it can continue testing throughout the process.

Last week, Microsoft announced its latest Insider Preview Build for developers testing pre-release updates of Windows 10. The build fixed issues that caused some people to see black screens when they tried to sign out and switch to other user accounts, said Windows and Devices Group software engineer Dona Sarkar in a blog post accompanying the release of Windows 10 Insider Preview Build 14931 for PC.

The latest build also addressed a problem that caused some Windows 10 apps, including the calculator, alarms and clock, not to work after updates to a new build, Sarkar said. She added that Microsoft is continuing to investigate some other issues that arose with a recent developer version of Windows 10 for Mobile. She said that a new build will be delayed until those problems, which affected the pin pad display and SIM card usage, are resolved.