Being ready to do this, I suppose you also read the warning in nLite that if you remove .CAT files, you will also get a lot of prompts about files not being digitally signed, right? I don't know if these prompts will break your unattended install, but it's worth doing another search and being completely informed of all the consequences. For example, I have about 50 of MS's updates and hotfixes; along with DirectX and driver catalog files (marked with oemxx where xx is a number), the size totals to about 9.5MB. It's not too big of a size, and how faster can it be? I have about 15-20 programs installing from RunOnce and at least that much add-ons, I haven't stripped a lot, and it still takes an hour total for a complete install. So, what I'm saying is have your options open and do a lot of test using a VM; if a quick install is all you're interested in, then disregard this. Enjoy