Overcoming Error 0x800f0926 During .NET Framework Installation in Windows Server 2012

Follow these detailed steps to fix the error code 0x800f0926 when installing .NET Framework 3.5 on Windows Server 2012:

1. Verify .NET Framework 3.5 status: Navigate to Control Panel > Programs and Features > Turn Windows features on or off. Check whether .NET Framework 3.5 is already activated.
2. Deploy the DISM command: Launch Command Prompt as an administrator and input: DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs (substitute D:\ with the appropriate drive letter of your installation media). This utilizes the installation media to install .NET Framework 3.5.
3. Run the Windows Update Troubleshooter: Access Control Panel > Troubleshooting > System and Security > Fix problems with Windows Update and follow the prompts to resolve any update-related issues.
4. Manually install .NET Framework 3.5: Visit the Microsoft Download Center, download the .NET Framework 3.5 installer, and execute the package following the instructions provided.
5. Scan for and repair system file corruption: Open Command Prompt as an administrator and execute: sfc /scannow to scan and repair any corrupted system files that could be causing the installation error.