Hello Haydee Mato,
BitLocker does not unlock with the MSN account password. What you need is the BitLocker recovery key, a 48‑digit numeric code that was generated when BitLocker was first enabled. That key is separate from the account password and is the only supported way to regain access to the encrypted drive.
The recovery key may have been saved automatically to your Microsoft account if BitLocker was enabled during setup. To check, sign in to another device with the same MSN/Outlook account and go to:
https://account.microsoft.com/devices/recoverykey
There you will see a list of recovery keys associated with your account. Compare the Key ID shown on the locked PC screen with the IDs listed online. Only the key with the matching ID will unlock the drive.
If the key is not in your Microsoft account, it may have been saved in one of these places: printed on paper, stored in a text file, saved to a USB drive, or backed up in Active Directory/Azure AD if the PC was domain‑joined. Without that recovery key, the encrypted data cannot be accessed. Microsoft designed BitLocker this way to ensure that only the rightful owner with the recovery key can unlock the drive.
Since you mentioned the PC is needed for an audit, I strongly recommend focusing on locating the recovery key in the above locations. If the MSN account password is forgotten, you can reset it through Microsoft’s account recovery process, but that will not substitute for the BitLocker recovery key.
I hope you've found something useful here. If it helps you get more insight into the issue, it's appreciated to accept the answer. Should you have more questions, feel free to leave a message. Have a nice day!
Domic Vo.