Currently I am using this to run Dell updates on non windows operating systems that are not directly supported.

imagex /mountrw c:\winpe_x86\winpe.wim 1 c:\winpe_x86\mount

imagex /unmount /commit c:\winpe_x86\mount

copy c:\winpe_x86\winpe.wim c:\winpe_x86\ISO\sources\boot.wim

oscdimg.exe -n -bc:\winpe_x86\etfsboot.com c:\winpe_x86\ISO c:\winpe_x86\dell.iso