How to: Determine which .NET Framework versions are installed

Users can install and run multiple versions of the .NET Framework on their computers. When you develop or deploy your app, you might need to know which .NET Framework versions are installed on the user’s computer.

The .NET Framework consists of two main components, which are versioned separately:

  • A set of assemblies, which are collections of types and resources that provide the functionality for your apps. The .NET Framework and assemblies share the same version number.

  • The common language runtime (CLR), which manages and executes your app's code. The CLR is identified by its own version number (see Versions and Dependencies).

Note

Each new version of the .NET Framework retains features from the previous versions and adds new features. You can load multiple versions of the .NET Framework on a single computer at the same time, which means that you can install the .NET Framework without having to uninstall previous versions. In general, you shouldn't uninstall previous versions of the .NET Framework, because an application you use may depend on a specific version and may break if that version is removed.

There is a difference between the .NET Framework version and the CLR version:

  • The .NET Framework version is based on the set of assemblies that form the .NET Framework class library. For example, .NET Framework versions include 4.5, 4.6.1, and 4.7.2.
  • The CLR version is based on the runtime on which .NET Framework applications execute. A single CLR version typically supports multiple .NET Framework versions. For example, CLR version 4.0.30319.xxxxx supports .NET Framework versions 4 through 4.5.2 and CLR version 4.0.30319.42000 supports .NET Framework versions starting with .NET Framework 4.6.

For more information about versions, see .NET Framework versions and dependencies.

To get a list of the .NET Framework versions installed on a computer, you access the registry. You can either use the Registry Editor to view the registry or use code to query it:

To get a list of the CLR versions installed on a computer, use a tool or code:

For information about detecting the installed updates for each version of the .NET Framework, see How to: Determine which .NET Framework updates are installed.

Find newer .NET Framework versions (4.5 and later)

Find .NET Framework versions 4.5 and later in the registry

  1. From the Start menu, choose Run, enter regedit, and then select OK.

    You must have administrative credentials to run regedit.

  2. In the Registry Editor, open the following subkey: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full. If the Full subkey isn't present, then you don't have the .NET Framework 4.5 or later installed.

    Note

    The NET Framework Setup folder in the registry does not begin with a period.

  3. Check for a DWORD entry named Release. If it exists, then you have .NET Framework 4.5 or later versions installed. Its value is a release key that corresponds to a particular version of the .NET Framework. In the following figure, for example, the value of the Release entry is 378389, which is the release key for .NET Framework 4.5.

    Registry entry for the .NET Framework 4.5

The following table lists the minimum value of the Release entry for each .NET Framework version. You can use these values as follows:

  • To determine whether a minimum .NET Framework version is present, test whether the Release DWORD value found in the registry is greater than or equal to the value listed in the table. For example, if your application requires the .NET Framework 4.7 or later, you test for a minimum release key value of 460798.

  • To test for multiple versions, begin with the latest .NET Framework version, and then test for each successive earlier version.

Important

The following table lists the keys of released versions of the .NET Framework only. It doesn't list the keys of preview or pre-release versions.

.NET Framework version Value of the Release DWORD
.NET Framework 4.5 378389
.NET Framework 4.5.1 378675
.NET Framework 4.5.2 379893
.NET Framework 4.6 393295
.NET Framework 4.6.1 394254
.NET Framework 4.6.2 394802
.NET Framework 4.7 460798
.NET Framework 4.7.1 461308
.NET Framework 4.7.2 461808

For a complete table of release keys for the .NET Framework for specific Windows operating system versions, see .NET Framework release keys and Windows operating system versions.

Find .NET Framework versions 4.5 and later with code

  1. Use the RegistryKey.OpenBaseKey and RegistryKey.OpenSubKey methods to access the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full subkey in the Windows registry.

    The existence of the Release DWORD entry in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full subkey indicates that the .NET Framework 4.5 or a later version is installed on a computer.

  2. Check the value of the Release entry to determine the installed version. To be forward-compatible, check for a value greater than or equal to the value listed in the .NET Framework version table.

The following example checks the value of the Release entry in the registry to find the .NET Framework 4.5 and later versions that are installed:

using System;
using Microsoft.Win32;

public class GetDotNetVersion
{
   public static void Main()
   {
      GetDotNetVersion.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 >= 461808)
            return "4.7.2 or later";
         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
Imports Microsoft.Win32

Public Module GetDotNetVersion
   Public Sub Main()
      Get45PlusFromRegistry()
   End Sub

   Private Sub Get45PlusFromRegistry()
      Const subkey As String = "SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full\"

      Using ndpKey As RegistryKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry32).OpenSubKey(subkey)
         If ndpKey IsNot Nothing AndAlso ndpKey.GetValue("Release") IsNot Nothing 
            Console.WriteLine(".NET Framework Version: " + CheckFor45PlusVersion(ndpKey.GetValue("Release")))
         Else 
            Console.WriteLine(".NET Framework Version 4.5 or later is not detected.")
         End If 
      End Using
   End Sub

   ' Checking the version using >= will enable forward compatibility.
   Private Function CheckFor45PlusVersion(releaseKey As Integer) As String
      If releaseKey >= 461308 Then
         Return "4.7.1 or later"
      Else If releaseKey >= 460798 Then
         Return "4.7"
      Else If releaseKey >= 394802 Then
         Return "4.6.2"
      Else If releaseKey >= 394254 Then 
         Return "4.6.1"
      Else If releaseKey >= 393295 Then
         Return "4.6"
      Else If releaseKey >= 379893 Then
         Return "4.5.2"
      Else If releaseKey >= 378675 Then
         Return "4.5.1"
      Else If releaseKey >= 378389 Then
         Return "4.5"
      End If
      ' 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"
   End Function
End Module   
' The example displays output like the following:
'       .NET Framework Version: 4.6.1

This example follows the recommended practice for version checking:

  • It checks whether the value of the Release entry is greater than or equal to the value of the known release keys.

  • It checks in order from most recent version to earliest version.

Check for a minimum-required .NET Framework version (4.5 and later) with PowerShell

  • Use PowerShell commands to check the value of the Release entry of the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full subkey.

The following examples check the value of the Release entry to determine whether the .NET Framework 4.6.2 or later is installed. This code returns True if it's installed and False otherwise.

# PowerShell 5
 Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full\' |  Get-ItemPropertyValue -Name Release | Foreach-Object { $_ -ge 394802 } 
# PowerShell 4
(Get-ItemProperty "HKLM:SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full").Release -gt 394802

To check for a different minimum-required .NET Framework version, replace 394802 in these examples with a Release value from the .NET Framework version table.

Find older .NET Framework versions (1–4)

Find .NET Framework versions 1–4 in the registry

  1. From the Start menu, choose Run, enter regedit, and then select OK.

    You must have administrative credentials to run regedit.

  2. In the Registry Editor, open the following subkey: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP:

    • For .NET Framework versions 1.1 through 3.5, each installed version is listed as a subkey under the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP subkey. For example, HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5. The version number is stored as a value in the version subkey's Version entry.

    • For .NET Framework 4, the Version entry is under the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4.0\Client subkey, the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4.0\Full subkey, or under both subkeys.

    Note

    The NET Framework Setup folder in the registry does not begin with a period.

    The following figure shows the subkey and its Version entry for the .NET Framework 3.5.

    The registry entry for the .NET Framework 3.5.

Find .NET Framework versions 1–4 with code

  • Use the Microsoft.Win32.RegistryKey class to access the HKEY_LOCAL_MACHINE\Software\Microsoft\NET Framework Setup\NDP subkey in the Windows registry.

The following example finds the .NET Framework 1–4 versions that are installed:

using Microsoft.Win32;
using System;

public static class VersionTest
{
    public static void Main()
    {
        GetVersionFromRegistry();
    }
    
    private static void GetVersionFromRegistry()
    {
        // Opens the registry key for the .NET Framework entry.
        using (RegistryKey ndpKey = 
                RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry32).
                OpenSubKey(@"SOFTWARE\Microsoft\NET Framework Setup\NDP\"))
        {
            foreach (var versionKeyName in ndpKey.GetSubKeyNames())
            {
                // Skip .NET Framework 4.5 version information.
                if (versionKeyName == "v4")
                {
                    continue;
                }

                if (versionKeyName.StartsWith("v"))
                {

                    RegistryKey versionKey = ndpKey.OpenSubKey(versionKeyName);
                    // Get the .NET Framework version value.
                    var name = (string)versionKey.GetValue("Version", "");
                    // Get the service pack (SP) number.
                    var sp = versionKey.GetValue("SP", "").ToString();

                    // Get the installation flag, or an empty string if there is none.
                    var install = versionKey.GetValue("Install", "").ToString();
                    if (string.IsNullOrEmpty(install)) // No install info; it must be in a child subkey.
                        Console.WriteLine($"{versionKeyName}  {name}");
                    else
                    {
                        if (!(string.IsNullOrEmpty(sp)) && install == "1")
                        {
                            Console.WriteLine($"{versionKeyName}  {name}  SP{sp}");
                        }
                    }
                    if (! string.IsNullOrEmpty(name))
                    {
                        continue;
                    }
                    foreach (var subKeyName in versionKey.GetSubKeyNames())
                    {
                        RegistryKey subKey = versionKey.OpenSubKey(subKeyName);
                        name = (string)subKey.GetValue("Version", "");
                        if (! string.IsNullOrEmpty(name))
                            sp = subKey.GetValue("SP", "").ToString();
                        
                        install = subKey.GetValue("Install", "").ToString();
                        if (string.IsNullOrEmpty(install)) //No install info; it must be later.
                            Console.WriteLine($"{versionKeyName}  {name}");
                        else
                        {
                            if (!(string.IsNullOrEmpty(sp )) && install == "1")
                            {
                                Console.WriteLine($"{subKeyName}  {name}  SP{sp}");
                            }
                            else if (install == "1")
                            {
                                Console.WriteLine($"  {subKeyName}  {name}");
                            }
                        }
                    }
                }
            }
        }
    }
}
// The example displays output similar to the following:
//        v2.0.50727  2.0.50727.4927  SP2
//        v3.0  3.0.30729.4926  SP2
//        v3.5  3.5.30729.4926  SP1
//        v4.0
//        Client  4.0.0.0
Imports Microsoft.Win32

Public Module VersionTest
    Public Sub Main()
        GetVersionFromRegistry()
    End Sub
    
    Private Sub GetVersionFromRegistry()

        ' Opens the registry key for the .NET Framework entry.
        Using ndpKey As RegistryKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry32). 
            OpenSubKey("SOFTWARE\Microsoft\NET Framework Setup\NDP\")

            For Each versionKeyName In ndpKey.GetSubKeyNames()
                ' Skip .NET Framework 4.5 and later.
                If versionKeyName = "v4" Then Continue For

                If versionKeyName.StartsWith("v") Then
                    Dim versionKey As RegistryKey = ndpKey.OpenSubKey(versionKeyName)
                    ' Get the .NET Framework version value.
                    Dim name = DirectCast(versionKey.GetValue("Version", ""), String)
                    ' Get the service pack (SP) number.
                    Dim sp = versionKey.GetValue("SP", "").ToString()
                   
                    Dim install = versionKey.GetValue("Install", "").ToString()
                    If String.IsNullOrEmpty(install) Then  ' No install info; it must be in a child subkey.
                        Console.WriteLine($"{versionKeyName}  {name}")
                    Else
                        If Not String.IsNullOrEmpty(sp) AndAlso install = "1" Then
                            Console.WriteLine($"{versionKeyName}  {name}  SP{sp}")
                        End If
                    End If
                    If Not String.IsNullOrEmpty(name) Then
                        Continue For
                    End If
                    For Each subKeyName In versionKey.GetSubKeyNames()
                        Dim subKey As RegistryKey = versionKey.OpenSubKey(subKeyName)
                        name = DirectCast(subKey.GetValue("Version", ""), String)
                        If Not String.IsNullOrEmpty(name) Then
                            sp = subKey.GetValue("SP", "").ToString()
                        End If
                        install = subKey.GetValue("Install", "").ToString()
                        If String.IsNullOrEmpty(install) Then  ' No install info; it must be later.
                            Console.WriteLine($"{versionKeyName}  {name}")
                        Else
                            If Not String.IsNullOrEmpty(sp) AndAlso install = "1" Then
                                Console.WriteLine($"{subKeyName}  {name}  SP{sp}")
                            ElseIf install = "1" Then
                                Console.WriteLine($"  {subKeyName}  {name}")
                            End If
                        End If
                    Next
                End If
            Next
        End Using
    End Sub
End Module
' The example displays output similar to the following:
'        v2.0.50727  2.0.50727.4927  SP2
'        v3.0  3.0.30729.4926  SP2
'        v3.5  3.5.30729.4926  SP1
'        v4.0
'        Client  4.0.0.0

Find CLR versions

Find the current CLR version with Clrver.exe

Use the CLR Version tool (Clrver.exe) to determine which versions of the CLR are installed on a computer:

Find the current CLR version with the Environment class

Important

For the .NET Framework 4.5 and later versions, don't use the Environment.Version property to detect the version of the CLR. Instead, query the registry as described in Find .NET Framework versions 4.5 and later with code.

  1. Query the Environment.Version property to retrieve a Version object.

    The returned System.Version object identifies the version of the runtime that's currently executing the code. It doesn't return assembly versions or other versions of the runtime that may have been installed on the computer.

    For the .NET Framework versions 4, 4.5, 4.5.1, and 4.5.2, the string representation of the returned Version object has the form 4.0.30319.xxxxx. For the .NET Framework 4.6 and later versions, it has the form 4.0.30319.42000.

  2. After you have the Version object, query it as follows:

    • For the major release identifier (for example, 4 for version 4.0), use the Version.Major property.

    • For the minor release identifier (for example, 0 for version 4.0), use the Version.Minor property.

    • For the entire version string (for example, 4.0.30319.18010), use the Version.ToString method. This method returns a single value that reflects the version of the runtime that's executing the code. It doesn't return assembly versions or other runtime versions that may be installed on the computer.

The following example uses the Environment.Version property to retrieve CLR version information:

using System;

public class VersionTest
{
    public static void Main()
    {
        Console.WriteLine($"Version: {Environment.Version}");
    }
}
// The example displays output similar to the following:'
//    Version: 4.0.30319.18010
Imports Microsoft.Win32

Public Module VersionTest
   Public Sub Main()
      GetVersionFromEnvironment()
   End Sub
   
    Private Sub GetVersionFromEnvironment()
        Console.WriteLine($"Version: {Environment.Version}")
    End Sub
End Module
' The example displays output similiar to the following:'
'    Version: 4.0.30319.18010

See also