After your unattended installation completes, the following temporary files exist in the root of the drive where the operating system was installed?

$LDR

SETUPLDR.bin

TXTSETUP.sif

$WIN_NT$.~BT (directory)

This behavior will occur if the \[MassStorageDrivers\] section of the Unattend.txt file contains controllers that are NOT physically present in the computer.

To workaround this behavior, specify only one boot controller entry in the \[MassStorageDrivers\] section and that driver is for the boot controller that is installed.

NOTE: You can also manually delete the above temporary objects after setup is complete.