Установленные версии платформы .NET Framework

using System;
using Microsoft.Win32;
 
public class GetDotNetVersion
{
   public static void Main()
   {
      Get45PlusFromRegistry();
   }
 
   private static void Get45PlusFromRegistry()
   {
      const string subkey = @"SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full\";
 
      using (var ndpKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry32).OpenSubKey(subkey))
      {
        if (ndpKey != null && ndpKey.GetValue("Release") != null) {
            Console.WriteLine($".NET Framework Version: {CheckFor45PlusVersion((int) ndpKey.GetValue("Release"))}");
        }
         else {
            Console.WriteLine(".NET Framework Version 4.5 or later is not detected.");
         }
      }
 
      // Checking the version using >= enables forward compatibility.
      string CheckFor45PlusVersion(int releaseKey)
      {
         if (releaseKey >= 528040)
            return "4.8 or later";
         if (releaseKey >= 461808)
            return "4.7.2";
         if (releaseKey >= 461308)
            return "4.7.1";
         if (releaseKey >= 460798)
            return "4.7";
         if (releaseKey >= 394802)
            return "4.6.2";
         if (releaseKey >= 394254)
            return "4.6.1";
         if (releaseKey >= 393295)
            return "4.6";
         if (releaseKey >= 379893)
            return "4.5.2";
         if (releaseKey >= 378675)
            return "4.5.1";
         if (releaseKey >= 378389)
            return "4.5";
         // This code should never execute. A non-null release key should mean
         // that 4.5 or later is installed.
         return "No 4.5 or later version detected";
      }
   }
}
// This example displays output like the following:
//       .NET Framework Version: 4.6.1