If you have administered a Windows Server 2012 R2 machine in the last five years, you have likely encountered a frustrating circular dependency. You try to install an application—an old SQL Server instance, a legacy ERP tool, or a critical monitoring agent—and it immediately fails, demanding .NET Framework 3.5 (includes 2.0 and 3.0).
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. The Complete Guide to Downloading and Installing the
The required file is located in the \sources\sxs folder of your Windows Server 2012 R2 installation ISO or DVD. Filename: microsoft-windows-netfx3-ondemand-package.cab On the "Confirm installation options" screen, look for
D:\sources\sxs (Replace D: with your actual drive letter).This guide addresses how to obtain and install the .NET Framework 3.5 feature on Windows Server 2012 R2, specifically focusing on the "Feature on Demand" method (using the .cab file) which avoids the need for Windows Update internet access. This guide addresses how to obtain and install the
| Error Code | Meaning | CAB Solution |
|------------|---------|---------------|
| 0x800f0906 | Source not found | Provide explicit /Source path to folder with CAB |
| 0x800f081f | Cannot locate source files | Ensure CAB is not corrupted; verify hash |
| 0x800f0954 | Group Policy prevents Update | Use /LimitAccess and local CAB |
In this blog post, we will discuss the .NET Framework 3.0 On-Demand Package CAB download for Windows Server 2012 R2. We will cover the following topics:
Error: "The source files could not be found"