When I was attempting to install SQL Server 2008 R2 on Windows Server 2008 R2, I was notified that the installer required Microsoft .NET 3.5 SP1 (Service Pack 1). The notification message states that I should visit http://www.microsoft.com/net to download and install the .NET 3.5 SP1 Framework.
Note: All pictures are click able and open the high resolution version in a new window.
The information outlined in the paragraph above is displayed in the image below:
Unfortunately, this will not resolve the issue. When you attempt to manually download and install the Microsoft .NET 3.5 SP1 (Service Pack 1) Framework on Windows Server 2008 R2, you will receive an error message that says “You must use the Role Management Tool to install or configure Microsoft .NET Framework 3.5 SP1″.
The information outlined in the paragraph above is displayed in the image below:
To correct this issue, you simply need to enable the Microsoft .NET 3.5 Framework from within the Features section of Server Manager. The steps are outlined below:
1. To open Server Manager, click the Start button on the menu bar, right click Computer, then click Manage. The image for this is provided below:
2. In Server Manager, click Features on the left then click add features on the right. The image for this is provided below:
3. Check the check box for .NET Framework 3.5.1 Features. The image for this is provided below:
4. Agree to add the required role services and features for the .NET Framework 3.5.1 by clicking Add Required Role Services. The image for this is provided below:
5. At this time, the check box for the .NET Framework 3.5.1 Features is selected. You can then click Next to begin the installation. The image for this is provided below:
6. On the Introduction to Web Server (IIS) screen, click Next. The image for this is provided below:
7. Verify that the .NET Extensibility check box is selected by default, and click Next. The image for this is provided below:
8. Click Install to finish the installation configuration and begin the installation. The image for this is provided below:
9. Wait for the progress bar to complete with the expected results. Please note that you’ll need to have local administrator rights to get past this step, or you’re get an error message. Additionally – the User Account Control (UAC) can give you issues during this time. I’m not a big fan of this feature so I simply disable that for Administrators with every server I work on (as long as my client’s infrastructure policy permits). The image for the progress bar on the installation is provided below:
10. Once the installation has completed, click Close and you’re all set. Notice the warning message in the image below about Windows Automatic Updating not being enabled. You’ll see this quite often – as most folks use different products to manage updates on production servers – such as Microsoft System Center Configuration Manager. The image for the completed installation is displayed below:
In case you were wondering why this happened – it’s because Windows Server 2008 R2 ships with the .NET 3.5.1 framework.
- Ira Bell

















