It performs an in-place update for the .NET Framework 4, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1 and 4.7.2.
https://support.microsoft.com/en-us/topic/microsoft-net-framework-4-8-offline-installer-for-windows-9d23f658-3b97-68ab-d013-aa3c3e7495e0
also this one could help.
https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/runtime/4.8-4.8.1
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