Looking for a list of Windows versions (service packs included) and what version of .NET is natively1 available.
Example:
Windows A - .NET Framework Z
Windows A Service Pack 1 - .NET Framework Z
Windows A Service Pack 2 - .NET Framework Y
1 By natively I mean that is there with no installs done.
This should give you all the answers you want:
https://en.wikipedia.org/wiki/.NET_Framework_version_history#Overview
Due to the fact that new versions of .NET are being released all the time I felt it would not be correct to try to embed the history into this answer, but merely direct you to a source which is updated.
