Sigh. Seems you learn by asking, but not reading or actually trying something. Well let me answer questions in numeric order. 1. encrypted install.esd have an ENCRYPTEDESD node inside their XML 2. WinNTSetup doesn't require wimlib for wimboot, if you use windows 8.1 upd 1. 3. Both using the "technique" on Windows 8.1 upd 1, but wimlib can do this experimental on older windows versions, too. 4. same as 3 5. the 1st of course, saving disk space is the purpose of wimboot 6. 3rd! 7. well yes, that the point of dynamic vhd's