This is the most direct way to install the package if you have the file or the installation ISO. Server Fault Mount your Windows Server 2012 R2 ISO or insert the installation media. Command Prompt as an Administrator. Run the following command (replace with the drive letter of your installation media):
Installing .NET Framework 3.5 on Server 2012 R2: Solving the microsoft-windows-netfx3-ondemand-package.cab Missing Issue
A common point of confusion is the fact that even on an up-to-date server running Windows Server 2012 R2, a simple attempt to install the .NET Framework 3.5 from the Server Manager will almost certainly fail. This is not a bug, but a design decision by Microsoft.
: Insert or mount your Windows Server 2012 R2 ISO. This is the most direct way to install
If you prefer a graphical interface, you must point the wizard to the "Alternate Source Path". Microsoft Dynamics Community Server Manager Add roles and features Proceed to the page and select .NET Framework 3.5 Features Confirmation page, click the link at the bottom: "Specify an alternate source path" Enter the path to the folder (e.g., D:\sources\sxs ) and click Microsoft Dynamics Community Method 3: PowerShell Installing .Net 3.5 on Windows 2012 R2 - Server Fault
In many enterprise environments, Server 2012 R2 instances are isolated from the internet (Air-Gapped). Attempting to enable the feature via the Server Manager GUI or standard PowerShell commands without a source path typically results in or 0x800F081F , indicating the source files could not be found. Installation Methodology
Windows Server 2012 R2 utilizes to reduce the operating system's footprint on storage drives. Unlike other features, the source files for .NET Framework 3.5 (which includes .NET 2.0 and 3.0) are not pre-cached in the Windows Side-by-Side ( WinSxS ) directory. Run the following command (replace with the drive
Open or PowerShell as an administrator.
Note: /LimitAccess ensures that DISM does not try to connect to Windows Update, focusing only on your provided source. Method 2: Server Manager (Alternative Source Path)
Use the OnDemand CAB as a local package
This is the most reliable method. If you have the Windows Server 2012 R2 ISO or DVD, mount it (e.g., as drive D: ) and run the following in an Administrative Command Prompt: powershell
If your server environment restricts public internet access, it will default to WSUS. However, WSUS by default unless explicitly configured to host them. Consequently, the operating system triggers a target source omission error, leaving your deployment incomplete.
For more detailed technical support on Windows components, you can search the Microsoft Learn platform . If you prefer a graphical interface, you must