I was trying to install an application on a VM running Server 2008 R2. The program required Microsoft’s .NET Framework 3.5 SP1 and wouldn’t install without it. Oddly, Windows Updates was installing updates for .NET Framework 3.5 and installing .NET Framework 4 didn’t work either. I tried downloading the .NET Framework 3.5 Service Pack 1 but when I ran the installer, I received this message: “You must use the Role Management Tool to install or configure Microsoft .NET Framework 3.5 SP1.”
Microsoft .NET Framework 3.5 SP1 comes with Windows Server 2008 R2 and has to be installed as a Feature through the Server Manager. This doesn’t seem to be something readily apparent until you receive these error messages.
Right-click on Computer and choose Manage… Then click on Features in the left column. On the right-side of the screen, click Add Features.
A dialog window will pop up. Expand .NET Framework 3.5 and check the box in front of .NET Framework 3.5.1 (or current version may change with Windows Updates). Then click the Next button to reach the confirmation screen. Then Click the Install button to complete the process of adding a feature.
After the install completes, you’ll receive a status report. As long as it says Installation successful, you can click the Close button and restart the computer as necessary.
After running through this process, I was able to successfully install the original application I wanted.
Here’s a walk-through of getting the error and adding the feature in video form, if you’d prefer: