BitLocker is full disk encryption software created by Microsoft software. It is designed to protect your PC against offline attacks and is intended to add an additional level of security, ensuring that only the authorized owner of the computer can unlock the device and restore access, typically if your device gets stolen. More information can be found here:
BitLocker was activated by someone and during the PC activation time it prompts the user to save/store the key in a safe place.
Use another secure computer or a smartphone to open the link.
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