Technical Guide to Overcoming Error 0x800f0818 in .NET Framework 3.5 Deployment on Windows Server 2008 R2

To resolve the error code 0x800f0818 while installing .NET Framework 3.5 on Windows Server 2008 R2, follow these essential steps:

1. Enable .NET Framework 3.5: Navigate to Server Manager > Features > .NET Framework 3.5 to check if it's enabled. If not, enable it and attempt the installation again.
2. Verify the installation source: Ensure that the installation source, such as a DVD or ISO file, is present and accessible.
3. Update and restart the server: Address any pending updates or restarts. Install necessary updates and reboot the server if required.
4. Use the DISM command for installation: Open Command Prompt as an administrator and execute the following command:

    dism /online /enable-feature /featurename:NetFx3 /all /source::\sources\sxs /LimitAccess

   Substitute with your installation source's drive letter.

5. Repair Windows Server 2008 R2: If the problem persists, consider using the installation media to repair the server. Boot from the media and choose the repair option.