Can I install High Sierra on Mac Mini 2011 and then install Sonoma as an upgrade in the OS rather then through USB?

Yes, you can install High Sierra on your Mac Mini 2011 and then upgrade to Sonoma within the operating system itself. Here's how you can do it:

1. Install High Sierra: Use the High Sierra installer to perform a clean installation on your Mac Mini 2011. You can download the High Sierra installer from the App Store or from Apple's website.

2. Prepare for Sonoma Upgrade: Before upgrading to Sonoma, ensure that your system meets the minimum requirements for Sonoma. This includes having compatible hardware and ensuring that your system is capable of running Sonoma smoothly.

3. Check Compatibility: Verify that all your hardware components and software applications are compatible with Sonoma. Check for any known compatibility issues and ensure that you have updated drivers and software for Sonoma compatibility.

4. Download Sonoma Installer: Once High Sierra is installed and running smoothly, download the Sonoma installer from the App Store or from Apple's website.

5. Backup Data: Before proceeding with the upgrade, it's essential to backup all your important data to prevent any data loss during the upgrade process.

6. Run Sonoma Installer: Launch the Sonoma installer from your Applications folder or from the location where you downloaded it. Follow the on-screen instructions to upgrade your system to Sonoma.

7. Upgrade Process: The upgrade process may take some time, depending on your system's hardware and the size of the upgrade files. Ensure that your Mac Mini is plugged into a power source and connected to the internet during the upgrade process.

8. Complete Installation: Once the upgrade process is complete, your Mac Mini will restart, and you'll be prompted to set up Sonoma. Follow the on-screen instructions to complete the setup process.

9. Post-Upgrade Verification: After upgrading to Sonoma, verify that all your hardware components and software applications are working correctly. Check for any compatibility issues and update drivers or software as needed.

By following these steps, you can upgrade your Mac Mini 2011 from High Sierra to Sonoma within the operating system itself, avoiding the USB installation method that you mentioned encountering issues with.