Windows 11 update KB5077181 issues: reboot loops and login problems

The February 2026 Windows 11 update KB5077181, released on February 10th as part of Patch Tuesday, has sparked a wave of user complaints. This update moves versions 24H2 and 25H2 to builds 26100.7840 and 26200.7840 respectively. While Microsoft's official page states there are no known issues, the reality on the ground tells a different story.

Users are reporting endless reboot loops after installing the update. In some cases, systems restart repeatedly 10-15 times in a row, never even reaching the login screen. The irony is that this update was supposed to finally fix the previous UNMOUNTABLE_BOOT_VOLUME error linked to problematic late-2025 updates. Instead of stabilization, some systems have gained new critical failures.

Even when devices do manage to boot, some encounter login errors related to the System Event Notification Service. Users see messages that the service failed to log on, with a 'specified procedure not found' error. There's no official explanation yet, but the problem appears precisely after installing KB5077181.

Network issues are also notable: after the update, some devices experience DHCP malfunctions, causing Wi-Fi connections to show as 'connected, no internet access.' In many cases, connectivity only returns after removing the patch. Installation errors with codes 0×800f0983 and 0×800f0991 are also being reported. Additional complications may affect users of specialized software—Wibu-Systems has warned about potential incompatibility with AxProtector protection mechanisms following the update.