Hi,
Thanks for your research and effort on this issue, I’m afraid you have to know that Windows 10 Enterprise can only be upgraded by downloading the latest version through the Volume License Service Center then performing a manual upgrade; or upgrading through Windows Update with Company Intranet.
If you want to upgrade to latest Enterprise version, you should register a MSDN/volume license account to download the latest version of win10 enterprise, and then do a clean install.
It’s not wise to use the evaluation version as the rest of your PCs are all Pro and the existed Activation key might not work contrary to usual condition and wipe out all data
While if you want to downgrade to Pro from Enterprise, it is not accepted as the link below
https://learn.microsoft.com/en-us/windows/deployment/upgrade/windows-10-upgrade-paths
I suggest you do a clean install with iso and buy the corresponding liscense
Before clean install, remember to backup all data you need using tools with official certificate which will be faster.
Hope this can help you
If your need further help, be free reply to me at your convenience.
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