If the installation fails (often with errors like or 0x800F081F ), consider these fixes: Install Net Framework 3.5 SP1 Offline on Server 2012 R2
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 If the installation fails (often with errors like
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 You need to mount the original Windows Server
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: Unlike modern features, these legacy components are not
Open (or an elevated Command Prompt) and run:
The microsoft-windows-netfx3-ondemand-package.cab file is the primary payload required to install (which includes .NET 2.0 and 3.0) on Windows Server 2012 R2. Unlike modern features, these legacy components are not stored in the local side-by-side (SxS) store by default to save disk space. This "Features on Demand" architecture necessitates pointing the installer to the original installation media or a specific CAB file when an internet connection to Windows Update is unavailable. Deployment Challenges
A "new" or uncorrupted CAB for Server 2012 R2 should have a digital signature from Microsoft. To verify: