Resolving Error Code 0x800f0926: Installing .NET Framework 3.5 on Windows Server 2012

To address the error code 0x800f0926 during the installation of .NET Framework 3.5 on Windows Server 2012, follow these steps:

1. Verify .NET Framework 3.5 installation: Navigate to Control Panel > Programs and Features > Turn Windows features on or off to check if .NET Framework 3.5 is already installed on your system.
2. Apply the DISM command: Launch Command Prompt as an administrator and enter: DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs (adjust D:\ to the drive letter of your installation media). This will initiate the installation of .NET Framework 3.5 directly from your media.
3. Run Windows Update Troubleshooter: Access Control Panel > Troubleshooting > System and Security > Fix problems with Windows Update, and execute the troubleshooter to resolve any update issues.
4. Manually install .NET Framework 3.5: Visit the Microsoft Download Center, download the .NET Framework 3.5 installer, and follow the prompts to complete the installation.
5. Inspect for corrupted system files: Open Command Prompt as an administrator and execute: sfc /scannow to scan and repair corrupted system files.