Devils0411, то же с выводом в файл:
Код:

@Echo Off
SetLocal EnableDelayedExpansion
Set ROOT=C:\Drivers
Set WSIF=C:\TEST\winnt.sif
PUSHD %ROOT%
For %%i In ("%ROOT%") Do If Exist %%i (Set ROOT=%%~si&Set $R=%%~nxsi) Else Exit
For /F "Delims=" %%i In ('DIR /B/S/A:D *') DO (
Set $D=%%~si
If Exist !$D!\*.inf Set OemPnPDriversPath=!OemPnPDriversPath!;!$R!!$D:%ROOT%=!
)
Echo [Unattended]>>"%WSIF%"
Echo OemPnPDriversPath="%OemPnPDriversPath:~1%">>"%WSIF%"