Fix FVE_E_VOLUME_BOUND_ALREADY (0x8031001F) on Windows

The 30-second fix: Check if you're actually encrypted

First off, open an admin Command Prompt and run:

manage-bde -status

What you're looking for is a column that says Conversion Status. If it says Fully Encrypted but you're getting the error, you're probably trying to bind a volume that's already been bound and encrypted in the past. That's the direct cause—the volume still has a key protector entry in the TPM or registry even though the encryption is complete.

The real fix here is simple: you don't need to do anything else. The volume is protected. The error just tells you Windows thinks you're trying to bind an already-bound volume. Stop whatever tool or script triggered this, and verify your data is actually encrypted via manage-bde -status. If it's fully encrypted, you're done.

But if the status is Used Space Only Encrypted or Encryption In Progress, you've got a deeper issue—the binding happened but encryption didn't complete. Move to the next section.

The 5-minute fix: Clear the key protector with manage-bde

If the volume isn't fully encrypted, we need to unbind it. What's actually happening here is that BitLocker's key protector (the piece that ties the volume to the TPM or a password) exists, but the volume's encryption metadata is incomplete. Windows blocks a second bind because it sees the protector.

From an elevated Command Prompt, run:

manage-bde -protectors -delete X: -type tpm

Replace X: with your actual drive letter. This removes the TPM protector without touching your data. Then verify:

manage-bde -status

You should see Key Protectors: None Found for that volume. Now you can re-enable BitLocker cleanly:

manage-bde -on X:

If you get an error about missing metadata, the volume's BitLocker header is corrupted. That's rare, but it happens after failed updates or disk clone operations. In that case, you'll need the longer fix below.

One gotcha: if the error says The volume is already bound to the system while you're trying to disable BitLocker, you need to use -protectors -delete -all on that volume first. That clears every protector, including the one causing the false binding state.

The 15+ minute fix: Force decryption and clean the volume header

This fix is for when manage-bde refuses to cooperate—maybe it throws The volume is already bound to the system even after deleting protectors, or you get The system cannot find the file specified when running manage-bde commands. The reason step 3 works is that a BitLocker volume header can get stuck in a semi-bound state, and the only way to reset it is to disable BitLocker entirely using the registry or a forced decryption.

Step 1: Backup your data. I mean it. The next command will mark the volume for decryption, but if the header is corrupt, you might lose access. Boot from a Linux live USB to copy files off if you're unsure.

Step 2: Force decryption via registry. Open Regedit as Admin, go to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\FVE\Volumes\{Volume GUID}

To find the GUID, run manage-bde -status and note the volume ID. Delete the entire key for that volume. This removes BitLocker's metadata from the OS's perspective. Reboot.

Step 3: Use diskpart to clean the partition. If the registry fix didn't work, the header is physically on disk. Open admin Command Prompt, run:

diskpart
list volume
select volume X
attributes volume clear hidden noerr
clean

Warning: This wipes the entire partition table entry. You'll need to recreate the volume afterward. The clean command removes the partition's metadata, including the bound state. This is the nuclear option—use it only if you've confirmed your data is backed up.

Step 4: Re-encrypt the drive. After the clean, the volume no longer exists. Create a new simple volume (or restore from backup), then run:

manage-bde -on X:

That'll set up a fresh binding with no prior state.

The core mechanic: BitLocker uses a structured header at the start of the partition to store protector information. When the header says bound but encryption isn't complete, Windows's FVE driver rejects any new binding operation. The only way to reset is to either delete the protector (manage-bde), delete the registry entry (if the header is intact but OS metadata is stale), or wipe the header itself (diskpart clean). Each step is more aggressive because the system's tolerance for corruption varies.

If none of this works, your drive might have hardware issues—bad sectors in the BitLocker metadata area can cause this error. Run chkdsk X: /f first to rule that out. But 95% of the time, the 5-minute fix with manage-bde -protectors -delete resolves it.