how do i get past bitlocker?

The Windows product key, Microsoft-account password and recovery key ID cannot substitute for the 48-digit BitLocker recovery password. A firmware change can trigger recovery, but restoring the BIOS does not guarantee access. Record each drive’s recovery key ID and check Microsoft accounts used during setup, former work/school accounts, printed copies and USB/text-file backups. If somebody else configured Windows, the key may be in their account. Preserve the encrypted drives and last year’s C-drive image before experimenting. That image may be useful if it contains saved recovery information or the OS state used for data-drive auto-unlock; Microsoft documents that auto-unlock information is stored on the OS volume. It does not guarantee recovery after restoring the image. Have a recovery specialist assess copies without overwriting the originals. Microsoft cannot recreate a lost key, and resetting or formatting removes data rather than unlocking it. Avoid those steps while recovering your unbacked-up files.