The bit locker key will not work

Dear Lorraine Roundy,

Thank you for reaching out to the Microsoft Q&A Forum.

The fact that the computer moved past the BitLocker screen and said "diagnosing your problem" means your BitLocker key is almost certainly correct. You successfully unlocked the drive.

The problem is not with BitLocker itself. The problem is that the part of Windows that is supposed to start after the drive is unlocked has become corrupted.

First, you need to access the Windows Recovery Environment. Then, you could try these solutions below to solve this issue:

1. Use the Advanced Repair Options:
   • From the "Choose an option" screen, select Troubleshoot > Advanced options > System Restore.
   • You may be asked to enter your BitLocker key again.
   • Choose your account and enter your password if prompted.
   • Select a restore point that is dated before the computer started having this problem and follow the on-screen instructions.
2. Use Command Prompt to repair boot files:
   • From the Advanced options screen, select Command Prompt.
   • You will likely need to enter your BitLocker key one last time.
   • A black command prompt window will open. Type the following commands one by one:

          bootrec /fixmbr 
          bootrec /fixboot 
          bootrec /scanos 
          bootrec /rebuildbcd
     

   • When you run the last command (/rebuildbcd), it will scan for your Windows installation. If it finds one, it will ask if you want to add it to the boot list. Press Y and then Enter.
   • Close the command prompt and restart your computer.
3. Final option: Reset this PC:
   • From the Troubleshoot screen, select "Reset this PC."
   • This is the most important step: You will be given two choices. Choose "Keep my files." This option will reinstall Windows, but it will preserve your personal data. You will have to reinstall your applications, but your important documents and photos will be safe.

I hope this could help. If you have any other issues, I'm very happy to assist.

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Dear Lorraine Roundy,

I haven't received the message from you yet. If there is anything more that I can do for you or if anything is unclear, please do not hesitate to let me know.

Warm regards.