In this blog post, we discussed the .NET Framework 3.0 On-Demand Package CAB download for Windows Server 2012 R2. We covered the different methods to download and install the package, including using the Microsoft Update Catalog, PowerShell, and Server Manager.
Installing the .NET Framework 3.5 on Windows Server 2012 R2 often requires a manual "On-Demand" installation because the source files are not pre-installed on the hard drive to save space. 1. Preparation: Locate the Source Files You need the original Windows Server 2012 R2 installation media (ISO or DVD). Server Fault Mount the ISO : Right-click your ISO file and select . Note the drive letter assigned (e.g., Target Folder : The required file ( microsoft-windows-netfx3-ondemand-package.cab ) is located in the \sources\sxs directory of that drive. Super User 2. Method A: Using Command Prompt (Recommended) This is the fastest method and bypasses common GUI errors. Super User Command Prompt as an Administrator. Run the following command, replacing with your actual mounted drive letter:
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs Use code with caution. Copied to clipboard : Enables all parent features of .NET 3.5. /LimitAccess : Prevents the server from trying to reach Windows Update. Wait for the progress bar to reach and show "The operation completed successfully". Super User 3. Method B: Using Server Manager (GUI) Install Net Framework 3.5 SP1 Offline on Server 2012 R2
To install .NET Framework 3.5 on Windows Server 2012 R2, you need the microsoft-windows-netfx3-ondemand-package.cab file, which is typically found on the original installation media. Because this feature is a "Feature on Demand," the required files are not pre-cached on the server's local drive and often fail to download automatically via Windows Update. Where to Get the CAB File
Microsoft does not provide a direct, standalone web download for this specific .cab file. You must extract it from a Windows Server 2012 R2 ISO: Location: Mount the ISO and navigate to \sources\sxs\. File Name: microsoft-windows-netfx3-ondemand-package.cab. How to Install (Standard Methods) Method 1: Command Line (Fastest)
Open a Command Prompt as Administrator and run the following command (replace D: with your mounted ISO drive letter):
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs Use code with caution. Copied to clipboard /All: Enables all parent features of .NET 3.5.
/LimitAccess: Prevents the server from trying to contact Windows Update, which often causes the process to hang. Method 2: Server Manager (GUI) Open Server Manager and click Add Roles and Features.
Proceed to the Features page and check .NET Framework 3.5 Features.
On the Confirmation page, click the link "Specify an alternate source path" at the bottom.
Enter the path to your sxs folder (e.g., D:\sources\sxs) and click OK then Install. Troubleshooting Common Errors Unable install NetFX3 into Windows server 2012R2
If you are looking for a "review" of using the microsoft-windows-netfx3-ondemand-package.cab
file to install .NET Framework 3.5 on Windows Server 2012 R2, the consensus among IT professionals is that it is a lifesaver for offline or restricted environments
, though it requires specific technical steps to work correctly. Professional Review: "The SysAdmin's Secret Weapon" Reliability: In this blog post, we discussed the
This method is often more reliable than the "Add Roles and Features" wizard when a server lacks a direct internet connection or is managed by a restrictive WSUS server. Efficiency: Instead of mounting a massive 3GB+ ISO just to grab the \sources\sxs folder, this small
file (usually around 70MB) provides the exact payload needed for the "Features on Demand" installation. Ease of Use: While not a "double-click" installer, the
command associated with it is straightforward for anyone comfortable with the command line. How to Use the Package Effectively
To ensure a successful installation on Server 2012 R2, follow this proven workflow: Place the File : Copy your downloaded microsoft-windows-netfx3-ondemand-package.cab to a local folder (e.g., C:\dotnet35 Run with Elevation : Open a Command Prompt or PowerShell as an Administrator Execute DISM
: Use the following command to point specifically to that file:
DISM.exe /online /enable-feature /featurename:NetFX3 /All /Source:C:\dotnet35 /LimitAccess Use code with caution. Copied to clipboard /LimitAccess flag is critical; it tells Windows
to try reaching out to Windows Update, preventing common timeout errors. Server Fault Common Pitfalls to Watch For Version Matching : Ensure the
file matches the OS version (Server 2012 R2). Using a file from a different version of Windows (like Windows 10 or Server 2019) can cause installation failures. Language Packs
: If you have multiple language packs installed, the installation might fail until they are removed, leaving only one primary language. WSUS Interference
: If your server is managed by WSUS, you may need to temporarily bypass it via registry or Group Policy to allow the feature to enable. Experts Exchange
For more detailed troubleshooting, you can refer to official documentation from Microsoft Learn or community discussions on Server Fault exact registry keys needed to temporarily bypass WSUS during this installation? Installing .Net 3.5 on Windows 2012 R2 - Server Fault
Installing .NET Framework 3.5 on Windows Server 2012 R2 often requires the microsoft-windows-netfx3-ondemand-package.cab file, as the source files are not installed by default to save disk space. This guide explains how to acquire the necessary files and resolve common installation errors using the Microsoft Evaluation Center and standard administrative tools.
How to Acquire the microsoft-windows-netfx3-ondemand-package.cab Meaning: DISM tried to reach Windows Update and failed
While many users look for a direct download for the standalone CAB file, it is officially distributed as part of the Windows Server 2012 R2 installation media.
Location on Media: If you have the ISO or physical DVD, the file is located in the \sources\sxs directory.
Official Source: You can download the full ISO from the Microsoft Evaluation Center to extract the required files.
Third-Party Alternatives: Some community forums provide the standalone CAB file, which is approximately 69 MB, but using official Microsoft media is recommended for security and compatibility. Step-by-Step Installation Guide
You can install .NET 3.5 using either the graphical interface or the command line. Method 1: Using Server Manager (GUI) Install Net Framework 3.5 SP1 Offline on Server 2012 R2
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:
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: why you might need it
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
Here’s a technical write-up covering the download, deployment, and use of the microsoft-windows-netfx3-onDemand-package.cab for Windows Server 2012 R2 in a modern (air-gapped or offline) scenario.
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.
Windows Server 2012 R2 does not include .NET Framework 3.5 full installation files by default. When you install or enable the .NET Framework 3.5 (which includes .NET 2.0 and 3.0), Windows tries to retrieve required files from Windows Update or from local installation media. The package commonly referenced for offline installations is named Microsoft-Windows-NetFx3-OnDemand-Package.cab. This article explains what that CAB is, why you might need it, and how to install .NET Framework 3.5 on Server 2012 R2 from local sources or a network share (without requiring direct internet access).
Even with a new CAB, you might see errors. Here’s how to fix them.
| Error Code | Meaning | Solution |
|------------|---------|----------|
| 0x800f081f | Source files not found | Ensure the folder path is correct and the CAB is not nested in subfolders. Use dir C:\Temp\NetFX3\*.cab to confirm. |
| 0x800f0906 | Cannot download from Windows Update | Add /LimitAccess to your DISM command to force it to use only the local CAB. |
| 0x800f0922 | Feature installation failed after reboot | Check Group Policy: Computer Config → Admin Templates → System → "Specify settings for optional component installation". Set to "Enabled" with alternate source. |
| 0x80070005 | Access denied | Re-run PowerShell/CMD as Administrator. |
| 0x800f0831 | CBS corruption | Run sfc /scannow and dism /online /cleanup-image /restorehealth first. |
After installation, verify success using:
Get-WindowsFeature -Name NetFx3 | Format-List Name, InstallState
Expected output: InstallState : Installed
Or check via Registry:
reg query "HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5" /v Install
Value 0x1 = installed.
Caution is paramount. Downloading system files from third-party websites poses significant security risks (malware, trojans, corrupted binaries). The only official sources for the microsoftwindowsnetfx3ondemandpackagecab for Server 2012 R2 are Microsoft properties.
DISM /Online /Get-Features | findstr NetFx3
DISM works even if the GUI "Add Roles" wizard fails.
Expected output: "The operation completed successfully." Reboot if prompted.