Thank you for posting on the HP Support Community.
BitLocker is a Microsoft software designed to protect your PC against offline attacks, unauthorized access typically if your PC gets stolen. BitLocker(Document might say windows 7 but its the same method for windows 10) is full disk encryption software. BitLocker was activated by someone and during the PC activation time, it prompts the user to save/store the key in a safe place.
Make sure you remove all the peripherals from this computer - unplug mouse/keyboards/any cables or accessories.
Press and hold the power-on button for 5-10 seconds until the computer powers off. Wait a few seconds and press the power button once to start the computer. Does it start fine now?
If it still doesn't start, power off the computer again. Start it and immediately begin hitting the Esc button repeatedly. HP Startup menu should come up. Press F10 to open BIOS and attempt to restore the BIOS settings to default ones. Save the changes and restart. (suggested by IT_WinSec)
This option has an option for a forgotten username, as well. Select "I know my password, but can't sign in" option and you will be able to log in via means of the phone number, etc... If you used your mobile phone number, this may help.
Hope this helps! Keep me posted for further assistance.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.
ECHO_LAKE I am an HP Employee
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