Troubleshooting Installation Issues with .NET Framework 3.5 on Windows Server 2019

To address the error code 0x800f0831 while attempting to install .NET Framework 3.5 on Windows Server 2019, follow these guidelines:

1. Verify .NET Framework 3.5 installation: Navigate to the Control Panel, access Programs and Features, and search for Microsoft .NET Framework 3.5 to see if it's already installed. If found, no further installation is necessary.
2. Implement the DISM tool: Launch Command Prompt with administrator rights and input: DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs. Adjust 'D:' to your installation media's drive letter. This will enable .NET Framework 3.5 installation directly from your media.
3. Run the Windows Update Troubleshooter: Access the Settings application, navigate to Update & Security, select Troubleshoot, and then choose Windows Update. Execute the troubleshooter and comply with the provided steps to rectify any Windows Update problems.
4. Search for Windows updates: Within the Settings application, proceed to Update & Security, select Check for updates, and install any updates found. Frequently, new updates can resolve installation issues with .NET Framework 3.5.
5. Utilize the .NET Framework Repair Tool: Acquire and execute the .NET Framework Repair Tool available from Microsoft's official site. This utility is designed to solve prevalent problems with .NET Framework setups.