MSDN details it here very nicely on how to check it from registry:
To find .NET Framework versions by viewing the registry (.NET Framework 1-4)
- On the Start menu, choose Run.
- In the Open box, enter regedit.exe.You must have administrative credentials to run regedit.exe.
In the Registry Editor, open the following subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP
The installed versions are listed under the NDP subkey. The version number is stored in the Version entry. For the .NET Framework 4 the Version entry is under the Client or Full subkey (under NDP), or under both subkeys.
To find .NET Framework versions by viewing the registry (.NET Framework 4.5 and later)
- On the Start menu, choose Run.
- In the Open box, enter regedit.exe. You must have administrative credentials to run regedit.exe.
In the Registry Editor, open the following subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full
Note that the path to the Full subkey includes the subkey Net Framework rather than .NET Framework
Check for a DWORD value named
Release
. The existence of the Release DWORD indicates that the .NET Framework 4.5 or newer has been installed on that computer.
Note: The last row in the above snapshot which got clipped reads On all other OS versions: 461310
. I tried my level best to avoid the information getting clipped while taking the screenshot but the table was way too big.