You are right, I was not take the time to check that before trying to implement these exclusion, they effectively leading to the same place.
Thanks, also I receive an email from ESET support about the issue on using system variable in File Security for Microsoft® Windows® Server 4.5.
You can see below, a small part of the email:
We can now confirm that it is not possible to create an exclusion in format %windir%\*.* in server products (v4 branch), however it is possible to do that in Endpoint products (v5). A request to add this option in v5 of server products has been sent to development.
PS: they mean V4