How to install/enable .Net 3.5 SP1 on Windows Server 2008 R2 for SQL Server 2008 and SQL Server 2008 R2

The .NET Framework 3.5 SP1 (also referred to as .NET Framework 3.5.1) is a prerequisite for SQL Server 2008. SQL Server 2008 Setup for standalone instance will install the .NET Framework 3.5 SP1 if it is not already installed. In Windows Server 2008 R2, the .NET Framework is a feature and installing it is different when compared to older versions of Windows Operating System. In previous versions, one could either download the .NET Framework 3.5.1 install binaries from Microsoft download site or use the install binaries from the redist folder of the SQL Server 2008 installation media. Starting with Windows Server 2008 R2, the method of installing .NET Framework 3.5.1 has changed. This document explains how to verify that .NET Framework 3.5.1 is installed and if it is not installed how you can add it.
How to verify if .NET Framework 3.5 SP1 is installed:

Here are the steps to verify that .NET Framework 3.5.1 is installed on Windows Server 2008 R2.

  1. Click the Start button in the lower left hand corner of the display.
  2. Highlight Administrative Tools and select Server Manager.
  3. In the Server Manager interface, click Features to display all the installed Features in the right hand pane. Verify that .NET Framework 3.5.1 is listed.

If .NET Framework 3.5.1 feature is not listed, you can use either of the following methods to install it:

Method 1: Using Server Manager Interface

  1. In the Server Manager interface, select Add Features to displays a list of possible features.
  2. In the Select Features interface, expand .NET Framework 3.5.1 Features.
  3. Once you expand .NET Framework 3.5.1 Features, you will see two check boxes. One for .NET Framework 3.5.1 and other for WCF Activation. Check the box next to .NET Framework 3.5.1 and click Next.
    Note: If you do not expand .NET Framework 3.5.1 Features and check it, you will get a pop-up titled Add Features Wizard  as shown below.

    Click Cancel and expand .NET Framework 3.5.1 Features and then check .NET Framework 3.5.1 check box below it.


    You cannot install .NET Framework 3.5.1 Features unless the required role services and features are also installed.
  4. In the Confirm Installation Selections interface, review the selections and then click Install.
  5. Allow the installation process to complete and then click Close.

Method 2: Using PowerShell

  1. Click the Start button in the lower left hand corner of the display.
  2. Highlight All Programs and select Accessories
  3. Expand Windows PowerShell and right click Windows PowerShell and select Run as administrator. Click Yes on the User Account Control box.
  4. At the PowerShell command prompt, type the following commands, and then press ENTER after each command:
  • Import-Module ServerManager
  • Add-WindowsFeature as-net-framework

Note: A screenshot is shown below:


Comments (21)

  1. Hi,

    is there any way to enable it, using a batchfile? i'm creating an install batch file, which installs SQL 2008, and .NET 3.5 on my servers. But some of the servers are under Windows 2008. installing .NET fails on them. What i have to do is what you said above. But I should do it using Batchfile. Would you please tell me how to do that?

  2. ahmsal1984 says:

    using System;

    using System.Diagnostics;

    namespace PrerequisiteHelper


    class Program


    static void Main(string[] args)


    ProcessStartInfo startInfo = new ProcessStartInfo();

    startInfo.FileName = "powershell.exe";

    startInfo.Arguments = "Import-Module ServerManager ; Add-WindowsFeature as-net-framework";

    startInfo.WindowStyle = ProcessWindowStyle.Hidden;

    startInfo.UseShellExecute = true;

    Process p = new Process();

    p.StartInfo = startInfo;







  3. I'v solved the problem,thanks a lot!

  4. Jamel says:

    Thanks for this little helpful post !

  5. Dattatraya says:

    you can uninstalled .net3.0 and 2.0  and install It

  6. David Borojevic says:

    Thanks – your first sentence answered my question after looking through various forums where others were also confused by inconsistent naming conventions for ,net;   many replies were from others thinking they knew the answer were just adding confusion:

    The .NET Framework 3.5 SP1 (also referred to as .NET Framework 3.5.1).


  7. Daniel Comp says:

    Thanks – funny how such a 'simple' thing can stop the whole show!

  8. Gyanendra says:

    I am also facing the same problem . and when I check in server manager it shows 3.5 is already installed. But  I run your command from command shell but problem is remain same. Please help me…

  9. avhacker says:

    one single line can do it, and you can put it in your batch file:

    powershell "Import-Module ServerManager; Add-WindowsFeature as-net-framework"

  10. avhacker says:

    One single line can do it, and you can put it in your batch file:

    powershell "Import-Module ServerManager; Add-WindowsFeature as-net-framework"

  11. Vikram says:

    Thanks for the detailed info…I solved the problem.

  12. I. Greß says:

    Thanks a lot, it was very useful.

    Greetings from Mexico

  13. 444 says:

    Installing a Windows language pack before installing the .NET Framework 3.5 will cause the .NET Framework 3.5 installation to fail. Install the .NET Framework 3.5 before installing any Windows language packs.

  14. chathuranga says:


    can i update .net framework 3.5 to 4.5. if any one know please help me

  15. Yogesh Mahto says:

    I'v solved the problem,thanks a lot!


    What does net framework  3.5 p1 do? Is it absolutely necessary?

  17. Roberto says:


    I have tried both suggested way, but:

    when I try trough server manage, at the end of the installation process, the system prompts that ita has been impossible to install all 3 services/roles required.

    If i try with PowerShell, I cannot import server manager module.

    Any clue on this?

    Thank you

  18. kk says:

    we upgrads the .netframework 3.5 to 4.0 in exchange server 2010 its impact to edge server 2010,2010 edge server support to .net framwork 4.0

  19. Mohsen says:


    When I try to install SQL server 2008, a message appear that .net framework 3.5 installing failed and need to this not 3.5.1 and problem not solved.

    Any idea?

  20. Thys says:

    Thank you !

  21. Opie-wan says:

    I think I am having the same problem as Mohsen (June 28 post)  

    I am trying to add SQL Server reporting services, and when I try to add features, the installer complains that .Net 3.5.1 installation failed and it is required for SQL Server.  When I look, I verify that .net 3.5 is installed, but I have searched all over and can not find nor figure out how to upgrade .Net 3.5 to .Net 3.5.1 on Windows Server 2012 R2.  The only option I am presented with in Server Manager is .Net 3.5, and it is installed.

    Can anybody point me in the right direction?  I think once I get the .Net framework SNAFU settled, the SQL Server install will probably work.