Vanguard UEFI Secure Boot Error | Steps to Fix

This is a specific error related to Valorant (and its anti-cheat, Vanguard) running on Windows 11. It means your computer is currently in “Legacy” or “CSM” mode, but the game requires the newer, more secure UEFI mode with Secure Boot and TPM 2.0 enabled.

Warning: Do not just flip switches in your BIOS without checking your drive format first. If you switch to UEFI mode while your hard drive is formatted as “MBR” (older standard), Windows will stop booting.

Follow these steps in exact order to fix it safely.

Phase 1: The Safety Check (Crucial)

Before entering your BIOS, you must verify your drive is ready for UEFI.

1. Press Windows Key + R, type diskmgmt.msc, and hit Enter.

2. Right-click your main Disk 0 (where Windows is installed) on the left grey side and select Properties.

3. Go to the Volumes tab and look at Partition Style.

   • If it says GPT: You are safe. Skip to Phase 3.

   • If it says MBR: You must convert it to GPT first (see Phase 2). If you skip this, your PC will not boot after changing BIOS settings.

Phase 2: Convert MBR to GPT (Only if needed)

If you are already GPT, skip this.

1. Open the Windows Start menu, type cmd, right-click Command Prompt, and select Run as Administrator.

2. Type this command to verify it’s possible: mbr2gpt /validate /allowFullOS

3. If it says “Validation completed successfully,” type this to convert: mbr2gpt /convert /allowFullOS

4. Once finished, your drive is now GPT and ready for the BIOS changes.

Also read : Wellcare Value Script Login

Phase 3: Enable Secure Boot & TPM in BIOS

You need to restart your computer and enter the BIOS menu.

• How to enter BIOS: Restart your PC and spam the Delete or F2 key immediately as it turns back on.

Here are the specific settings for the major motherboard brands:

ASUS

1. Press F7 for “Advanced Mode”.

2. Go to Boot > Secure Boot.

3. Change OS Type to Windows UEFI Mode.

4. (If Secure Boot says “Active: No”): Go to Key Management > Install Default Secure Boot Keys.

5. For TPM: Go to Advanced > PCH-FW Configuration > Enable PTT (Intel) or fTPM (AMD).

MSI

1. Press F7 for “Advanced Mode”.

2. Go to Settings > Advanced > Windows OS Configuration.

3. Change BIOS UEFI/CSM Mode to UEFI.

4. Go to Secure Boot > Secure Boot Mode > Standard.

5. Set Secure Boot to Enabled.

6. For TPM: Go to Security > Trusted Computing > Enable Security Device Support.

Gigabyte

1. Press F2 for “Advanced Mode”.

2. Go to the Boot tab.

3. Find CSM Support and set it to Disabled. (Secure Boot will not appear until CSM is disabled).

4. Go to Secure Boot and toggle it to Enabled.

5. For TPM: Go to Settings > Miscellaneous > Enable Intel Platform Trust Technology (PTT) or AMD CPU fTPM.

ASRock

1. Go to the Security tab > Secure Boot.

2. Set Secure Boot to Enabled.

   • Note: If it gives an error saying “Install keys,” change Secure Boot Mode to Custom, click Install Default Secure Boot Keys, then switch it back to Standard.

3. For TPM: Go to Advanced > CPU Configuration > Enable AMD fTPM Switch (or Intel PTT).

Phase 4: Verify the Fix

1. Press F10 in BIOS to Save & Exit. Your PC should reboot into Windows.

2. Once in Windows, press Windows Key + R and type msinfo32.

3. Check these two lines:

   • BIOS Mode: Should say UEFI.

   • Secure Boot State: Should say On.

If both match, open Valorant. The error should be gone.