What Is Secure Boot? Follow the Trust Chain From UEFI to Windows

Secure Boot adds an important layer of protection before Windows fully starts, helping block untrusted software from loading during the boot process. In detail, what is secure boot actually?

Get to know this process through our article to reduce the risk of boot-level malware while supporting a more secure Windows environment.

1. What Is Secure Boot and How Does It Work?

Secure Boot is a security feature built into UEFI firmware that helps prevent untrusted software from loading during startup. It checks the digital signatures of boot-related components and allows them to run only when they match trusted certificates stored in the system.

When the computer starts, Secure Boot verifies items such as bootloaders and other critical startup code before passing control to the operating system. If a signature is valid, the component is allowed to continue; if it is missing, altered, or untrusted, Secure Boot can block it from running.

This verification process helps defend against bootkits, rootkits, and other malware that attempts to load before Windows starts.

2. Secure Boot vs. UEFI vs. TPM: What Is the Difference?

Secure Boot, UEFI, and TPM all contribute to system security, but they perform very different jobs during startup and everyday operation. Understanding what is secure boot becomes easier when you see how it fits alongside firmware management and hardware-based security.

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3. How to Check If Secure Boot Is Enabled

Checking Secure Boot status does not require changing firmware settings immediately. Both Windows and Linux provide ways to verify whether the feature is active, although the exact tools and commands differ by operating system.

Checking on Windows

Windows includes a built-in System Information utility that shows both the current BIOS mode and Secure Boot status. This is the easiest method for most users because it does not require entering UEFI settings or restarting the computer.

• Open the Start menu and search for System Information.
• Select the System Information app from the results.
• In System Summary, locate BIOS Mode.
• Confirm that BIOS Mode shows UEFI rather than legacy.
• Find Secure Boot State in the same list.
• If it displays On, Secure Boot is currently enabled.
• If it displays Off, the feature is supported but not active.
• If it shows Unsupported, the system may be using Legacy BIOS mode or hardware that does not support Secure Boot.

Checking on Linux

Linux users can verify Secure Boot from the terminal, commonly with tools such as `mokutil` when the distribution provides it.

The result reports whether Secure Boot is enabled at the firmware level, making it unnecessary to restart into UEFI just to confirm the current state.

• Open a terminal window.
• Run the command mokutil –sb-state if mokutil is installed.
• Read the returned status message.
• SecureBoot enabled means the feature is currently active.
• SecureBoot disabled means the machine is booting without Secure Boot enforcement.
• If Mokutil is unavailable, install it through your distribution’s package manager or use distribution-specific Secure Boot tools.
• Remember that Linux Secure Boot support can depend on the bootloader, signed kernel components, and how the distribution is configured.

4. Common Secure Boot Problems and How to Fix Them

Secure Boot issues often appear after firmware changes, Windows upgrades, hardware replacements, or security requirements from certain games. Before changing UEFI settings, identify the exact problem first, since enabling the wrong option or altering boot mode can prevent Windows from starting correctly.

Secure Boot Option Is Grayed Out

When Secure Boot cannot be selected, the PC may still be using Legacy BIOS or Compatibility Support Module (CSM) mode instead of full UEFI mode.

Microsoft notes that Secure Boot requires UEFI, so check the firmware boot configuration and switch from Legacy/CSM to UEFI when the system supports it. Some motherboards may also require administrator-level firmware access before the setting becomes editable. 

PC Will Not Boot After Enabling Secure Boot

Boot failure after enabling Secure Boot can occur when Windows was installed under Legacy/CSM mode, the disk configuration is incompatible, or a boot component lacks a trusted signature.

Rather than repeatedly toggling settings, return to the previous firmware configuration first. Then verify UEFI compatibility, boot-disk setup, and firmware requirements before trying Secure Boot again.

Games Still Report a Secure Boot Error

Games with anti-cheat systems may require Secure Boot to be both supported and actively enabled, rather than simply showing UEFI capability. 

For example, Valorant may report security-related errors when its required Secure Boot or TPM configuration is not satisfied. Check Windows System Information to confirm Secure Boot State shows “On,” then review TPM 2.0 and the game’s current security requirements if the warning continues

Secure Boot Keys Are Missing

Secure Boot relies on firmware key databases such as the Platform Key (PK), Key Exchange Key (KEK), allowed signature database (db), and forbidden signature database (dbx). 

If required keys are missing or undefined, Secure Boot may remain in Setup Mode or fail to validate boot components correctly. Use the motherboard manufacturer’s restore or factory-key option when available rather than creating or replacing keys manually unless you understand UEFI key management.

5. Frequently Asked Questions about Secure Boot

Secure Boot can sound confusing because it is often discussed alongside UEFI, BIOS settings, TPM, and game security requirements. These quick answers clarify what the feature actually does and why it matters in modern Windows systems.

What is UEFI secure boot?

UEFI Secure Boot is a security feature built into modern UEFI firmware that checks the digital signatures of boot-related software before allowing it to run. Its purpose is to help prevent untrusted bootloaders and certain types of malware from starting before the operating system.

What is secure boot in BIOS?

The phrase “Secure Boot in BIOS” usually refers to the Secure Boot setting found inside a computer’s firmware menu. Technically, Secure Boot is a UEFI feature rather than a traditional legacy BIOS feature, so the system generally needs to use UEFI mode for it to work properly.

What is UEFI secure boot for Valorant?

For Valorant, Secure Boot is part of the security environment used by Riot Vanguard on supported Windows systems. If the game reports a Secure Boot-related error, confirm that the PC is running in UEFI mode and that Secure Boot is actually enabled, not merely supported.

6. Final Thoughts

Secure Boot plays a key role in protecting the startup process by allowing only trusted, digitally signed components to load before Windows begins. Once you understand what is secure boot, it becomes easier to see how UEFI, TPM, firmware keys, and system security work together.

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