Resolving error code 0x800f0818: Feature installation issue in Windows Server 2012 R2

Here are various methods to resolve the error code 0x800f0818:

1. Update your system: Ensure your Windows Server 2012 R2 is running the latest updates. Navigate to Settings > Update & Security > Windows Update and click Check for updates.
2. Utilise the DISM tool: Open Command Prompt with administrative privileges and enter the command: DISM /Online /Cleanup-Image /RestoreHealth. This will check and repair any corrupted files on your system.
3. Run the System File Checker: Open Command Prompt with administrative rights and type: sfc /scannow. This will inspect and repair any corrupted system files.
4. Temporarily disable antivirus software: Antivirus programs can sometimes block feature installations. Temporarily disable your antivirus software and attempt the installation again.
5. Use Windows Server installation media: If the previous steps fail, try using the Windows Server installation media for feature installation. Insert the media, run setup.exe, choose the option to upgrade your current installation, and follow the prompts to finish the process.