Microsoft has resolved a significant bug affecting Windows users since August 12, which hindered the migration from Windows 10 to 11 and caused various issues, including installation errors and data corruption. The upgrade issue was particularly problematic for users transitioning from Windows 10 version 1809 to Windows 11 22H2 and 23H2, as well as for Windows Server upgrades, with many encountering error code 0x8007007F. Microsoft confirmed the fix on August 18, although it was available as early as August 15. The latest versions, Windows 11 version 24H2 and Windows Server 2025, were not affected by these issues. Users are urged to upgrade from Windows 10 before October 14 to avoid losing essential security updates.