What's the type of the ISO? I mean auto installation or manual installation? With GUI or without GUI?
i remember this didn't work on windows 7, i made an office 2019 iso but it didn't work do you know any workaround
Use office 2016 ( office 2019 not supported anymore , leave windows 7 install windows 10 ltsc 2021.... better
Better use linux ... ubuntu mate ( aka ubuntu with fork of old gnome .... like windows 10 motor with windows xp look light and fast )
ubuntu is a resource intensive more than windows 7, especially the latest few versions, if you mean some older versions like maybe ubuntu 14, but that would be not safe as it reached end of life last april