What does HRESULT 0x8031009C (FVE_E_EFI_ONLY) mean?

Status / error code:

Category:

Constant name:

Source:

Facility:

Operating System:

Description:

The feature is only supported on EFI systems.

Previous	Next
FVE_E_INVALID_DATUM_TYPE	FVE_E_MULTIPLE_NKP_CERTS

FVE_E_EFI_ONLY

Read this as a state-machine result

FVE_E_EFI_ONLY is a BitLocker facility HRESULT, not a Win32 filesystem error wrapped by an application. In this case the requested BitLocker feature depends on UEFI services and cannot run on a legacy BIOS boot path.

Note: Hardware-encrypted drives add firmware, storage-driver and drive-security state below the normal BitLocker volume provider. When diagnosing this result, remember: BitLocker can reject the hardware path before conversion starts, and policy may or may not permit a fallback to software encryption.

What the code does not prove

The closest misleading interpretation is FVE_E_FIRMWARE_TYPE_NOT_SUPPORTED, which can cover a broader unsupported firmware configuration for OS-volume enablement. Verify the returning method and state transition before assigning the incident to disk corruption, TPM failure or bad credentials.

Inspect the target, not just the message

record firmware mode, disk partition style, active boot loader, Secure Boot state and the feature being invoked. Keep the full HRESULT and the first method that returned it because later cleanup calls can report a different state.
capture manage-bde -status and the protector inventory for the exact volume GUID, not only the drive letter, because letters can change in WinRE, clusters and deployment environments.
Export BitLocker operational events for the result failure and note the boot session, caller identity and management source; that evidence separates this BitLocker condition from a generic access or storage error.

Note: Firmware, storage drivers and security-band state can change independently. When diagnosing this result, remember: A successful filesystem check does not validate the eDrive management channel.

A low-risk recovery path

migrate to a supported UEFI/GPT boot configuration through documented deployment procedures before retrying the feature.
After correcting the result prerequisite, refresh protection, conversion and lock state before one controlled retry; a cached UI message is not proof that the condition is still active.
Before a this result remediation deletes protectors, changes firmware mode, resizes partitions or decrypts a production drive, verify that an independent recovery method is available and escrowed in the intended directory or account.

manage-bde -status
powershell -NoProfile -Command "Get-CimInstance -Namespace root/cimv2/security/MicrosoftVolumeEncryption -Class Win32_EncryptableVolume"

Result Interpretation

After correction, compare the new conversion, protection and lock state with the original snapshot. A different HRESULT after this result is useful because it means the request crossed this boundary and reached the next prerequisite.

State checks specific to it

Checkpoint	How to interpret it for it
Before the call	Record the target identity and the pre-call hardware-encrypted drive negotiation state. The decisive boundary is that the requested BitLocker feature depends on UEFI services and cannot run on a legacy BIOS boot path.
At failure	Preserve firmware mode, disk partition style, active boot loader, Secure Boot state and the feature being invoked. This proves whether it came from BitLocker itself or from a wrapper translating another result.
After correction	Migrate to a supported UEFI/GPT boot configuration through documented deployment procedures before retrying the feature. The request should then advance without removing an unrelated recovery route.
After reboot or remount	Recheck protection, conversion and lock state for it; a successful management call is incomplete if the next boot cannot unlock the volume.

Verification after the change

Success means more than the absence of a dialog. Confirm that the condition represented by it now matches the intended design, that the protector inventory has not lost an independent recovery route, and that the next reboot or remount can unlock the volume. If the request advances to another HRESULT, record both values in order because that transition reveals the next unmet prerequisite.

References

Reference set for it:

Looking for a different code? Search another status or error code.