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Registry: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full

The registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full and its values lists the installed version of the .NET Framework version 4.5 and later.
Thus, the presence of this key along with a value named Release indicates that the .NET Framework 4.5 or later is installed.

Release

The value of Release determines, depending on the Windows version (!) which .NET

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How to: Determine which .NET Framework versions are installed

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