Another solution to this would be to install an inexpensive WIFI adapter, or alternatively plug in a phone for USB wifi tethering. This would allow the OP to proceed with a normal installation with internet.Motherboard too new for native network support in Win11 and since Microsoft removed 'no network connection' to proceed with installation makes it difficult. Why o why did they do that. There is a work around, hopefully command prompt still works.
View: https://www.reddit.com/r/buildapc/comments/ykow7m/gigabyte_z790_aero_g_networking_drivers_for/?
Here's a little workaround for anyone having that problem and can't use the above solutions.
Install win 10 that has no mandatory internet connection to install. When you are done do a win 11 upgrade through windows update.
From what i know, the upgrade to win 11 is free if you have 10. You can even upgrade to 11 with non activated 10 and then use the 11 key to activate it.Thats the first thought . But if you havent already a copy win 11 than try to get one . Good luck !