Error switching phone to BP Pass through mode
To get around this issue, once you get a Device driver could not be installed message from Windows, don't close RSDLite nor power off the phone. Start Motorola Driver Installer once again, and let it finish. Then if RSDLite didn't timeout yet, head to Device Manager, find the Unknown device, and in its properties' Driver tab click Update driver…. It should now install normally. If RSDLite timed out and you got an error from it, just repeat the SBF process. The driver should now be present, and the flashing process will finish normally.
Once the flashing process is complete, RSDLite will tell you to “power the phone up manually”. In most cases you won't be able to do this straight as instructed: the phone will be bootlooping. Take the battery out, and then place it back in. Press the lock/power button: the phone should boot normally.
Close RSDLite. Disregard the warning about flashing not being completed since your phone has already booted into Android.