@terenet the smallest size I got with NTLite in version 1909 without compromising important features and without integrating .NET 3.5 was 771 MB for ISO and 662 MB for install.esd. To get less than that I would have to remove support for printers, VPN, mobile internet (4G) among other things. With windows 8.1 I believe it is possible to get less than 700 MB but with windows 10 I think it is very difficult or requires a lot of knowledge. But the size of the ISO does not make the slightest difference in performance what matters is the services running in the background so with an ISO of 800 MB or 900 MB you will not notice any differences. Search for "ivankehayov" in piratebay. Your last ISO which is based on LTSC 2019 is around 900 MB and appears to be very stable. In addition he is a known member here on the forum.