Trying to install Windows 11 version 25H2 and hitting error 0x800f0991 can feel exhausting. The update starts, progress moves, then suddenly it fails and rolls back. Your PC still works, but the update does not finish, and that wastes time. This article explains what the error means, why it happens, how to fix it step by step, and how to reduce the chance of seeing it again. What Is Windows 11...

