Before you attempt to download or install the driver, you must prepare your system to ensure the installation doesn't fail. Follow these preparatory steps:
The "Nokia Bootmgr Driver" for Windows 7 is a specialized driver primarily used for low-level communication with Nokia Lumia and other Windows Phone devices when they are in a recovery or bootloader state. It is essential for "unbricking" devices that fail to start up properly or get stuck on screens such as the "spinning gears". Nokia Bootmgr Driver Windows 7