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:Windows Server 2012 R2/2016/2019 solution to not install. NET Framework 3.5.1 or language pack

Last Updated:Dec 15, 2020

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Problem description

This article introduces the following two problem phenomena.


Symptom 1: unable to install the. NET Framework

The following error is returned when you install. Windows Server 2012 R2 in Windows Server 2016, Windows Server 2019, or NET Framework 3.5.1.


Symptom 2: unable to install language pack

You cannot select or install a language pack when switching languages in the control panel or querying language options in Windows Update.


Possible cause

As WSUS(Windows Server Update Services) is used by Windows instances by default to obtain Update sources, the installation files of the. NET Framework and language package are missing. Then an error is reported, either the source file cannot be found or the language pack cannot be installed.



Alibaba Cloud reminds you that:

  • Before you perform operations that may cause risks, such as modifying instance configurations or data, we recommend that you check the disaster recovery and fault tolerance capabilities of the instances to ensure data security.
  • You can modify the configurations and data of instances including but not limited to Elastic Compute Service (ECS) and Relational Database Service (RDS) instances. Before the modification, we recommend that you create snapshots or enable RDS log backup.
  • If you have authorized or submitted sensitive information such as the logon account and password in the Alibaba Cloud Management Console, we recommend that you modify such information in a timely manner.

The solution is as follows:

  1. Find PowerShell from the Start menu, right-click and select run as administrator.
  2. Run the following command to modify the registry and set the Update source to Windows Update.
    Set-ItemProperty -Path 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU' -Name UseWUServer -Value 0
    Restart-Service -Name wuauserv
  3. Run the following command to install the. NET Framework driver through PowerShell.
    Install-WindowsFeature Net-Framework-Core
    Note: You can also continue to install. NET Framework in Server Manager or install language packs in the console panel.
  4. After the. NET Framework and language pack are installed, run the following command to change the Windows Update source to WSUS:
    Note: This is an optional step, you can also continue to use Windows Update as the Update source.
    Set-ItemProperty -Path 'HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU' -Name UseWUServer -Value 1 Restart-Service -Name wuauserv



For more information about why the. NET Framework cannot be installed, refer to the following contents.

  • If Windows Server 2012 and Windows Server 2016 use high memory resources, installing other applications will consume more memory. The installation of the. NET Framework may fail due to insufficient memory. Therefore, we recommend that you increase the physical memory. For I/O optimized instances, you can enable virtual memory as appropriate.
  • If 0x800f081f is reported when you install the. NET Framework, check whether the Internet is working properly. If the connection is normal, the Update may fail due to an unstable connection to the Windows Update Server. We recommend that you change the time period and try again.


Application scope

  • ECS