Fixing Error Code 0x800f0926 for .NET Framework 3.5 on Windows Server 2012

To resolve the error code 0x800f0926 while installing .NET Framework 3.5 on Windows Server 2012, follow these steps:

1. Verify .NET Framework 3.5 status: Navigate to Control Panel > Programs and Features > Turn Windows features on or off to check if .NET Framework 3.5 is already enabled.
2. Install using DISM: Launch Command Prompt as an administrator and execute: DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs (adjust D:\ to match your installation media's drive letter). This uses your installation media to install .NET Framework 3.5.
3. Run Windows Update Troubleshooter: Access the troubleshooter via Control Panel > Troubleshooting > System and Security > Fix problems with Windows Update to resolve update issues.
4. Manually install .NET Framework 3.5: Download the installer from the Microsoft Download Center and follow the installation instructions provided.
5. Scan for corrupted system files: Open Command Prompt as an administrator and type: sfc /scannow. This command scans and repairs corrupted system files that might be preventing the installation.