May I ask what are the reasons why Windows Update reports error code C8000266? Is the only reason that Datastore.edb has a maximum file size limit? I'm asking this question because, before applying the ESU License Preparation patch, my freshly installed Windows Server 2008 SP2 can detect all patches before the ESU support start date, but as soon as I apply KB4474419, KB4493730 and activate the ESU license (either use TSForge or use BypassESU), Windows Update only reports error C8000266with no other results, no matter how many times I tried. I did apply the Vista datastore.edb fix, but nothing changed afterwards. During the execution of the script, it prompted that the system denied it access to the wuaueng file, and I needed to manually change the owner of the file to Administrator to resolve this issue.
It's not related to the files size itself https://forums.mydigitallife.net/threads/restore-windows-update-for-vista.82336/page-14#post-1774183 you should install ESU servicing stack updates on stages, and do not install both ESU License Preparation Packages together see the tips in ReadMe this might only work for x64 only, even with the datastore.edb fix x86 handle or require memory that might not be available