Windows 11 reaches 1 billion users, but remains embroiled in controversy over critical flaws

Microsoft’s operating system celebrates a historic milestone in global adoption, driven by the end of support for Windows 10, although the latest security updates generated serious technical problems that forced the company to release emergency patches.

Windows 11 has reached 1 billion active users globally, according to Europa Press, solidifying its position as Microsoft’s dominant operating system after the end of official support for Windows 10. However, this achievement comes amid significant controversy, following the release of security updates in January that caused numerous critical failures on various computers.

The company stopped providing support for Windows 10 in October of last year, which meant the end of software updates, security updates, and technical assistance. This decision prompted millions of users to migrate to Windows 11, although Microsoft offered an additional year of security updates through the paid ESU program, in addition to providing free access to these updates in the European Union.

In this context, Microsoft CEO Satya Nadella described the 1 billion user milestone as «important» during the presentation of the company’s fiscal second quarter 2026 results, as reported by The Verge. The growth represents a year-over-year increase of over 45%, with adoption rates faster than those of Windows 10, which took more than three years to reach similar figures.

However, the strong growth of Windows 11 coincided with a challenging start to the year for the company. Security updates released on January 13, corresponding to versions 23H2 (KB5073455) and 24H2 and 25H2 (KB5074109), caused bugs that prevented users from shutting down or hibernating computers, as well as problems with Virtual Desktop, Windows 365, and Outlook crashes.

To mitigate these issues, Microsoft released several out-of-band (OOB) updates available on its Windows 11 Known Issues page. However, even after installing these patches, some users began reporting a more serious error that prevents the system from booting, particularly affecting those who installed update KB5074109.

According to reports from outlets like Neowin and AskWoody, Microsoft confirmed that some devices are displaying the ‘UNMOUNTABLE_BOOT_VOLUME’ error, forcing users to perform manual recovery procedures. The company acknowledged that it is still working on a partial solution, but warned that this will not prevent the problem from occurring or repair the computers that can no longer boot, leaving the historic growth of Windows 11 marked by technical uncertainty.

Source: www.itsitio.com