To install .NET Framework 3.5 (identified by the package name
Microsoft-Windows-NetFx3-OnDemand-Package~31bf3856ad364e35~amd64~~.cab Windows Server 2012 R2
, you typically cannot download a standalone installer from the internet. Instead, you must use the installation media as a source or use specific DISM commands. Microsoft Learn Primary Installation Methods Using DISM with Installation Media (Recommended) The most reliable way is to use the Deployment Image Servicing and Management (DISM)
tool. You need to mount the original Windows Server 2012 R2 ISO or insert the DVD. Mount your installation media (assume drive letter Command Prompt as an Administrator. Run the following command:
dism /online /enable-feature /featurename:NetFx3 /all /limitaccess /source:D:\sources\sxs Using PowerShell You can achieve the same result via PowerShell
Install-WindowsFeature Net-Framework-Core -Source D:\sources\sxs Using Server Manager (GUI) Server Manager Add roles and features Proceed to .NET Framework 3.5 Features Confirmation page, click Specify an alternate source path at the bottom. Enter the path to the folder (e.g., D:\sources\sxs Microsoft Learn Common Troubleshooting Error 0x800F0906 / 0x800F081F: To install
These usually occur when the server cannot reach Windows Update or the specified source path is incorrect. Ensure the path leads directly to the folder containing the file (usually \sources\sxs on the disk). Internet Access:
If the server has unrestricted internet access and is not managed by WSUS, it may attempt to download the files automatically. However, for most production servers, using the offline installation media is the standard practice. WSUS Interference:
If your server is connected to WSUS, it may fail to find the package. You may need to bypass WSUS by adding /LimitAccess to your DISM command or adjusting the Group Policy
"Specify settings for optional component installation" to "Contact Windows Update directly". Spiceworks Community exact registry settings to bypass WSUS for this installation, or do you need help mounting the ISO
Install .NET 3.5 Windows server 2012 R2 - Spiceworks Community for most production servers
After installation completes (progress bar 100%), verify success:
Get-WindowsFeature -Name NetFx3 | Format-List InstallState
You should see: InstallState : Installed
Alternatively, check Registry: HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5 – the Version key should exist.
Once the .cab file is placed on the target server (e.g., C:\Temp\), you have two primary deployment options.
Microsoft does not offer a standalone direct download for just the CAB file. You must extract it from an official ISO. However, you can use the DISM /Online /Enable-Feature /FeatureName:NetFx3 /All without any source – this forces Windows Update. Only use that if your server has internet access. To install
The .NET Framework 3.0 On-Demand Package is a set of installation files that allow you to install the .NET Framework 3.0 on a Windows Server 2012 R2 system. This package is also known as the ".NET Framework 3.0 On-Demand Package CAB" or "dotnetfx35ondemand.msp".
The .NET Framework 3.0 On-Demand Package CAB file contains the necessary files to install the .NET Framework 3.0 on a Windows Server 2012 R2 system. This package is usually required when you need to install an application that depends on the .NET Framework 3.0.
Meaning: The .cab version does not match your server’s image. Solution: The "new" cab you downloaded may be for a different build (e.g., Server 2016, or a different cumulative update level). Extract the .cab from a Windows Server 2012 R2 ISO with the same Service Pack or update level as your running server.
Meaning: DISM tried to reach Windows Update and failed.
Solution: Add the /limitaccess flag to prevent online checks, or configure your local group policy: Computer Configuration → Administrative Templates → System → Specify settings for optional component installation and component repair → Enable → Alternate source path.