Hi Bob,
I'm Dyari. Thanks for reaching out. I will be happy to assist you in this regard.
If you enabled BitLocker by yourself, try to recover it:
https://support.microsoft.com/en-us/windows/fin...
If it has been locked automatically, contact the manufacturer's support services to help you out with this matter:
https://support.hp.com/us-en/document/c06458046
For troubleshooting steps, kindly check out the links below:
https://answers.microsoft.com/en-us/windows/for...
https://www.tenforums.com/tutorials/37060-turn-...
https://www.tenforums.com/tutorials/36701-turn-...
If none of these worked for you, unfortunately, the only option would be performing a hard disk format which leads to wiping out all data.
Please let me know if you need further assistance and keep me updated.
____________________________________________________________
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.s