BitLocker drive encryption information message

Hi everyone,
I have some issue with Windows BitLocker Drive.
My laptop was on standby and when I wanted to continue working on it I got error message.
I don't know what is the problem and why I got this message.
Can someone help me with this?
My OS is Windows Vista
Windows Bitlocker Drive Encryption Information
The system boot information has changed since Bitlocker was enable.
You must supply a Bitlocker recovery password to start this system.
Confirm that the changes to the system boot information are authorized.
If the changes to the system boot information are trusted, then disable and re-enable Bitlocker.
This will reset Bitlocker to use the new boot information otherwise restore the system boot information.
Thanks,
William
