How to Install .NET 3.5 on Windows 11

This post shows students and new users how to install the .NET 3.5 framework in Windows 11 to support dot NET apps.

.NET 3.5 framework isn’t going away anytime soon. Some older apps still require it to function, and until all apps update .NET 3.5 requirements, we’ll still be using it to support these legacy applications.

The new Windows 11 will also have .NET packages available and ready to install when needed. Windows 11 will come with many new features and enhancements that will work great for some while adding some learning challenges for others.

Some things and settings have changed so much that folks must learn new ways to manage Windows.

Even though Windows 11 has many new features and functionalities, it still hasn’t removed .NET from its code base. It will support legacy applications that still require it to function.

To get started installing the .NET 3.5 framework in Windows 11, follow the steps below:

Install .NET framework via Windows features

There are many ways to install .NET and enable it in Windows 11. One of the fastest ways to get .NET 3.5 in Ubuntu is via Windows add/remove features.

To get the Windows features pane, click Start and search for “Turn Windows features on or off.” Then click on the relevant link as shown in the image below:

When the Windows features pane opens, select and check the box next to .NET frame 3.5 (includes .NET 2.0 and 3.0). Once chosen, click OK to install.

When prompted with the screen below, select “Let Windows Update download the files for you” and continue with the installation. The required file should be downloaded and installed quickly, depending on your internet connection speed.

.NET 3.5 framework should be installed and ready to use. You may want to reboot as well.

Download and Install .NET 3.5 Framework in Windows 11

Another way to install the .NET 3.5 Framework in Windows 11 is to download and install the package. If you can’t access the Windows features above, download the .NET 3.5 packages and install them. To do that, click on the link below:

Download .NET Framework 3.5 SP1 | Free official downloads (microsoft.com)

Click the link on the site above to download and install the package.

Once downloaded, click on dotnetfx35.exe to run the installer. When prompted, choose “Download and install this feature” and continue.

Windows Update will fetch and download all the required packages and install them on your system. Wait until all is downloaded and installed, then reboot to complete the installation.

After a brief moment, DOT NET 3.5 should be installed and ready to use. You may have to reboot to complete the installation.

Install .NET 3.5 Framework in Windows 11 from Command Prompt.

Yet another way to install the .NET 3.5 framework in Windows 11 is via the Command Prompt. To do that, open the command prompt as administrator by searching and right-clicking the app and selecting Run as administrator, shown below:

When the Command Prompt app opens, run the commands below to install the .NET 3.5 framework.

Dism /online /Enable-Feature /FeatureName:"NetFx3"

The command above will initial the .NET 3.5 installation. After the installation, you will see a message similar to the one below.

Deployment Image Servicing and Management tool
Version: 10.0.22000.1

Image Version: 10.0.22000.71

Enabling feature(s)
[==========================100.0%==========================]
The operation completed successfully.

Install .NET 3.5 via PowerShell in Windows 11

Finally, another way to install .NET 3.5 in Windows 11 is via Windows PowerShell. Open PowerShell as administrator by searching for it, right-clicking, and selecting to run as administrator.

When Windows PowerShell opens, run the commands below to install .NET 3.5.

Enable-WindowsOptionalFeature -Online -FeatureName "NetFx3"

How to install the .NET 3.5 framework offline in Windows 11

Sometimes, you may have to install the .NET 3.5 framework offline using a Windows 11 installer ISO image.

This option does not use an internet connection to install .NET and can be useful if you cannot install .NET Framework 3.5 using any of the other options above.

First, download Windows 11 ISO. Once downloaded, mount the ISO file in File Explorer.

Next, open the command prompt as administrator.

Then, run the commands below to install .NET Framework 3.5.

Dism /online /enable-feature /featurename:NetFX3 /Source:<drive letter>:\sources\sxs /LimitAccess

I am replacing the <drive letter> with the one used to mount Windows 11 ISO files.

That should do it!

Conclusion:

• Installing the .NET 3.5 framework in Windows 11 is essential for supporting legacy applications that still rely on it.
• Multiple installation methods are available, including using Windows features, downloading the package, utilizing the Command Prompt, and leveraging PowerShell.
• For users without internet access, the offline installation using a Windows 11 ISO is a practical option.
• Each method is straightforward and can be completed in a few steps, making it accessible for all users.
• Ensuring that .NET 3.5 is installed will enhance compatibility with older applications and improve overall system functionality.