Fixing The Errors Installing Microsoft .NET Framework 3.5 in Windows 8/8.1/10

Microsoft .NET Framework is one of the most important add ons that need to be installed in Windows. Luckily Windows 8 or above come with the latest version of .NET Framework pre-installed. In this article, we will look at some of the ways of installing the earlier versions of .NET Framework and fixing the problems that may occur during installation.

Why is .NET Framework 3.5 important?

While the latest version of may be .NET Framework 4.5.2 which comes pre-installed in Windows 8.1, there is always a need for the earlier version of the framework which is necessary to run applications requiring the version 3.5 or earlier specifically. Version 3.5 can also be installed along side version 4 or above. This is why it’s important to have .NET Framework 3.5 installed on your system for older applications to work properly.

There are various ways of installing the framework. Some of them are discussed below:

Installing .NET Framework 3.5 on demand

If you are installing an app which requires .NET Framework 3.5 but doesn’t find it on the system, it will automatically show the following dialog. You will only need to select Install This Feature to automatically download and install the framework. This will include both version 2.0 and 3.5 so that the application has all the required files for execution.

.NET Framework 3.5 installation on demand

Installing .NET Framework 3.5 from the Control Panel

If you want to install .NET Framework 2.0 and 3.5 yourself, you can follow the steps below:

  1.  Go to Control Panel –> Programs and Features (Windows Key + X + F)
    .NET Framework 3.5 add Windows features
  2. On the left hand menu, select Turn Windows Features on or off. You can also open this directly using Run –> OptionalFeatures.
    .NET Framework 3.5 enable the framework

This will download all the required components from the Internet and automatically install the framework for you.

Installing .NET Framework 3.5 in offline mode without connecting to the Internet

If you don’t have an Internet connection, you’ll need to follow the steps below to install the framework in offline mode. Make sure you have the Windows 8 or 8.1 DVD or the source files to install the framework in offline mode. Otherwise, you can download .NET Framework 3.5 offline installer from the below location and install it by double clicking the downloaded setup.

If you don’t have an active Internet connection, Windows will give the following error:

“Windows couldn’t connect to the Internet to download necessary files. Make sure that you’re connected to the Internet, and click Retry to try again.”

  1.  Open command prompt with Administrative privileges (Windows Key + X + A)
    .NET Framework 3.5 installing via command prompt
  2. Issue the following command:
    Dism /online /enable-feature /featurename:NetFx3 /All /Source:D:\Sources\sxs /LimitAccess
    Where D:\Sources\sxs is the path to your Windows DVD or the source.
    If you prefer using the PowerShell, run the following command in PowerShell:
    Install-WindowsFeature –name NET-Framework-Core –source D:\sources\sxs
  3. This will enable the feature and will let you know when the process is complete.

Download .NET Framework 3.5 offline installer

If none of the methods for installing works, then you can just download the standalone installer of .NET Framework 3.5 and install it anywhere you want.

Download .NET Framework 3.5 from here.

Troubleshooting the errors during installation of the framework

0x800F081F and 0x800F0906 errors

These are the most common errors that you will encounter while installing .NET Framework 3.5.  Here’s an explanation of both the codes:

0x800F081F – The source files could not be found

0x800F0906 – The source files could not be downloaded

If you are connected to the Internet and still are encountering this issue, this is because you have installed the following Windows updates:

  1. KB2966826
  2. KB2966827
  3. KB2966828

These are the security updates for .NET Framework 3.5 which must be installed on the current installation of the framework. But since Microsoft applies these updates regardless of whether framework 3.5 is installed or not, they get installed even when the framework is not installed.

If these updates are installed first and then you try to install the framework, you will get the above mentioned errors. You will need to uninstall the above mentioned updates, install the .NET Framework 3.5 through one of the methods mentioned above and finally install the updates again.

.NET Framework 3.5 uninstalling Windows Updates

Using Group Policy to control the installation

If the above mentioned method doesn’t work and you still can’t install the framework, just follow the instruction below and try again:

  1. Open Group Policy Editor ( Run –> gpedit.msc)
  2. Go to the following hive:
    Computer Configuration –> Administrative Templates –> System
  3. In the right hand pane, enable the following:
    Specify settings for optional component installation and component repair
    .NET Framework 3.5 controlling Windows Update through group policy

Hopefully this will let you install the .NET Framework 3.5 without any further errors. If you are still having problems with your installation, please let us know through comments below and we’ll try to solve the problems for you.

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Usman Khurshid
Usman Khurshid is a seasoned IT professional. He has been working in the IT industry for the last 15 years. From making a simple network including physical cabling to consulting for SMEs about cloud computing, he has vast experience in the computing industry. He is also certified in Microsoft Technologies (MCTS and MCSA) and also Cisco Certified Professional on Routing and Switching.