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WALKER BEX›VALORANT›GUIDE 41
VALORANT · TPM 2.0 · UEFI BOOT

VAN 9001 MBR to GPT? Guide

Validate your boot setup before attempting an unnecessary disk conversion.

Walker Bex Guides••7 min read
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The quick answer

TPM detection and disk conversion are different issues.

VAN 9001 is associated with TPM/security checks; it does not automatically mean your disk must be converted. Verify TPM with tpm.msc and BIOS mode with msinfo32. MBR-to-GPT conversion matters only if your Windows installation actually uses Legacy/MBR and you need UEFI/Secure Boot for the error shown.

Jump into the guide

01Interactive conversion pre-flight

Confirm each item before any system-disk changes

mbr2gpt /validate /allowFullOS
The validation command checks eligibility; it does not convert the disk. In Windows, launch an elevated Command Prompt and target the OS disk only.

02MBR and GPT are not the same as TPM

TPM problem (VAN 9001)

TPM 2.0 is a firmware/hardware security capability. Start with tpm.msc and the motherboard vendor’s TPM guidance.

Legacy boot and Secure Boot

A legacy/MBR Windows installation may need proper GPT/UEFI migration before Secure Boot can operate. That is a separate issue, frequently associated with a Secure Boot message.

03Validation-first migration plan

  1. Record current disk and boot status

    Use Get-Disk in PowerShell or the Disk Management properties to identify the OS disk partition style.

  2. Run only validation at first

    Read the exact result of mbr2gpt /validate /allowFullOS. If validation fails, stop.

  3. Back up and plan recovery

    Conversion changes the boot structure; ensure you can recover Windows and have your encryption keys.

  4. Follow Microsoft and your OEM’s migration procedure

    Microsoft documents the conversion utility and the subsequent UEFI firmware switch. Do not flip CSM off on an unconverted installation.

  5. Verify Windows boots before enabling Secure Boot

    Check msinfo32 afterward, then follow your OEM Secure Boot instructions if the actual Vanguard message requires it.

Frequently asked questions

Does VAN 9001 mean I must convert MBR to GPT?

No. First confirm whether the actual problem is TPM 2.0, UEFI boot, or Secure Boot.

Will MBR2GPT guarantee no lost data?

It is designed for nondestructive conversion, but all disk/firmware changes carry risk. Back up and verify prerequisites.

Sources & update notes

Original Walker Bex explanations. Technical guidance checked October 15, 2026; follow the current linked support instructions if they change.