BitLocker Error 0XC0210015: Startup Key or Recovery Password Not Found

What Does Error 0XC0210015 Mean?

When you boot your Windows PC and see this error, BitLocker is telling you it can't find the encryption key. The exact message reads: "The BitLocker encryption key could not be obtained from the startup key or the recovery password."

This error shows up most often after a BIOS/UEFI update, a motherboard replacement, or when you've messed with drive letters in Disk Management. It can also pop up if your TPM (Trusted Platform Module) got reset or disabled.

The good news: you don't need to wipe your drive. In most cases, you can fix this in under a minute. Let's start with the simplest thing to try.

The 30-Second Fix: Check Your USB Startup Key

If you set up BitLocker to use a USB startup key (instead of TPM-only), the computer needs that USB drive plugged in at boot. Here's what to check:

1. Look for the USB drive — Is it plugged into the same port as before? Try a different USB 2.0 port on the back of the PC. USB 3.0 ports can be flaky during POST.
2. Check the drive letter — The USB key must have the exact same drive letter as when you created it. If you changed it, the key won't be found.
3. Test the USB drive in another computer — Does it show up? Can you read the file called BEK or BDE on the root? If the drive is dead, you'll need a backup key or the recovery password.

What you should see: If the USB is working and the drive letter matches, the computer should boot past the error. If it doesn't, move to the next step.

The 5-Minute Fix: Use the Recovery Password

If you have your 48-digit BitLocker recovery password, you can skip the startup key entirely. You usually saved this when you first turned on BitLocker — it might be in your Microsoft account, a printed document, or a text file on a different drive.

Where to find the recovery password

• Microsoft account — Go to https://account.microsoft.com/devices/recoverykey and sign in. Look for a key ID that matches the one shown on your error screen.
• Printed or saved file — Check your email, a printed sheet, or a file named BitLocker Recovery Key.txt.

Once you have the password, type it in when prompted during boot. Use the function keys (F1–F10) to enter numbers. Press Enter after each block of 6 digits.

What you should see: After entering the full password, Windows should boot normally. You'll then see a prompt to suspend or disable BitLocker so it doesn't ask again. Do that — then re-enable BitLocker with your current hardware setup. If the password doesn't work or you can't find it, we have one more option.

The 15+ Minute Fix: Repair BitLocker from the Command Line

This is for when the USB key is lost, the recovery password is missing, but you still have access to Windows through another boot method (like a recovery drive or a second Windows install).

Warning: This requires administrative access to the encrypted drive. If you don't have that, you're stuck — you'll need to format the drive and restore from backup.

Step 1: Boot into a recovery environment

• Insert a Windows installation USB or recovery drive.
• Boot from it. Select your language, then click Repair your computer (bottom-left corner).
• Go to Troubleshoot → Advanced options → Command Prompt.

Step 2: Identify your encrypted drive

At the command prompt, type:

manage-bde -status

Look for the drive letter (usually C: or D:) that shows BitLocker: On. Note the drive letter.

Step 3: Try to unlock the drive with a recovery password

If you have the recovery password, type:

manage-bde -unlock C: -RecoveryPassword YOUR-48-DIGIT-PASSWORD

Replace C: with your drive letter. Replace YOUR-48-DIGIT-PASSWORD with the actual password (no dashes).

What you should see: "The volume was successfully unlocked." If it says the password is invalid, you're out of luck with this method.

Step 4: Remove the existing startup key and add a new one

If the unlock worked, you can clear the old key and set a new USB key. Connect a blank USB drive (it will be formatted). Then run:

manage-bde -protectors -delete C: -type StartupKey
manage-bde -protectors -add C: -StartupKey E:

Replace E: with your USB drive letter. After this, try booting normally with the USB plugged in.

What you should see: The command should confirm the protector was added. Reboot with the USB drive — the error should be gone.

Step 5: If nothing works — disable BitLocker (destructive)

If you can't unlock the drive at all, your only option is to wipe it. From the recovery command prompt, use:

diskpart
list disk
select disk X
clean

This erases EVERYTHING on the drive, including BitLocker encryption. You'll need to reinstall Windows and restore from backup.

Don't do this unless you have a backup. I've seen too many people lose everything because they skipped the backup step.

Final Thoughts

Error 0XC0210015 is scary, but it's almost never a sign of a dead drive. Nine times out of ten, the fix is plugging in the right USB key or typing a recovery password. If you're still stuck after these steps, your TPM might have failed. Check if TPM is enabled in BIOS and try clearing it (but that will break BitLocker for sure — you'll need the recovery password after).

If you're in a corporate environment, your IT department might have a BitLocker recovery key escrow in Active Directory. Call them before you try anything destructive.