Thanks Enthousiast and Aboddi1406 for the explanations. Indeed I'm currently using W10UI with resetbase and .Net 3.5 enabled. Yes, I'm aware that it breaks the reset option, but that's actually what I want . I understand that by using either method (integrating it in the image or enabling it post deploy) .Net 3.5 will get updated by the CU afterwards. It may be needed to re-run the CU after everything has been setup to have WU satisfied. Cheers.