To enable Secure Boot on a Gigabyte motherboard, follow these summarized steps:

1. Enter BIOS by pressing the Del or F2 key during system startup.
2. Ensure your system is running in UEFI mode (not Legacy BIOS) and your boot drive uses GPT partition style.
3. Disable CSM (Compatibility Support Module) support from the Boot section in BIOS.
4. Enable TPM (fTPM for AMD CPUs or PTT for Intel CPUs) in the BIOS settings, usually under Security or Miscellaneous.
5. Navigate to the Secure Boot option in the BIOS (often under Security or Boot tab).
6. Enable Secure Boot and if prompted, install the default Secure Boot keys.
7. Save and exit the BIOS (usually by pressing F10), then reboot.

After rebooting, check Secure Boot status inside Windows by running "msinfo32" and looking for "Secure Boot State" which should say "On." Make sure your BIOS firmware is up to date for the best compatibility. Note: Sometimes you may have to set Secure Boot mode to Custom, restore factory keys, then switch back to Standard mode. Also, a GPT partition and disabled CSM are prerequisites, or your system may not boot with Secure Boot enabled. These steps are verified for Gigabyte motherboards including models like Z590 and B450M and are compatible with Windows 11 requirements.