I get an error on 1st boot when trying to call WIHU from the cd. The error is can't find path \software\wihu\wihu.exe, yet when I double click the cmd file on the cd/dvd it works fine.

Therefore is it the way i'm calling the cmd file from winnt.sif or the cmd?

wihu.cmd (located %CDROM%\$OEM$\$1\install)

cmdow @ /HID
@echo off


IF EXIST D:\CD.txt set CDROM=D:
IF EXIST E:\CD.txt set CDROM=E:
IF EXIST F:\CD.txt set CDROM=F:
IF EXIST G:\CD.txt set CDROM=G:
IF EXIST H:\CD.txt set CDROM=H:
IF EXIST I:\CD.txt set CDROM=I:
IF EXIST J:\CD.txt set CDROM=J:

ECHO.
start /wait %CDROM%\Software\wihu\wihu.exe /skiprestart /skipsettings /usecurrent /autologon 
ECHO.
EXIT

winnt.sif

[GUIRunOnce]
%Systemdrive%\install\wihu.cmd

Problem solved.

Someone forgot to put cd.txt in root dir of dvd.