Go to Control Panel / Programs / Programs and Features / View Installed Updates
Use the Search Box to search the updates for
Or if you prefer, search the list your self
Look in the registry for the following keys
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NET Framework\v4.0.30319\SKUs\
.NETFramework, Version=v4.0.1 .NETFramework, Version-v4.0.1, Profile=Client
.NETFramework, Version=v4.0.1
.NETFramework, Version-v4.0.1, Profile=Client