Is the server from the internet, or managed via WSUS/SCCM ?
Microsoft hosts many feature on-demand packages on the .
I can provide the exact scripts or registry fixes tailored to your network configuration. Share public link Is the server from the internet, or managed via WSUS/SCCM
Ensure you point to the parent folder \sources\sxs and not directly to the file name itself.
The error 0x800f081f explicitly confirms that Windows cannot locate the payload files required for .NET Framework 3.5, which is a "Feature on Demand" and not stored locally in the WinSxS folder by default. When your server is domain-joined or configured to use a WSUS (Windows Server Update Services) server, the problem is exacerbated. Since WSUS servers do not typically store optional feature content like .NET 3.5, your server attempts to reach out to a source that doesn't have the files, and the installation fails. Share public link Ensure you point to the
This is a more permanent and manageable solution.
The file is a feature-on-demand package that contains all the necessary source files for installing .NET Framework 3.5 (which includes .NET 2.0 and 3.0). In newer versions of Windows, the core files for this older framework aren't stored on the system drive after installation, which is why the standard "Add Roles and Features" wizard fails. This .cab file acts as a source to make the installation possible. Since WSUS servers do not typically store optional
The most official source is from Microsoft itself. The company hosts many of its updates on the Windows Update servers. A direct download link (which remains functional) for the .cab file is:
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:C:\Temp
Is your server completely or connected to a WSUS server ?
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.