Hello and welcome to JustAnswer, I look forward to assisting you today. Can you provide me a little more explanation as to what the problem is please?
What version of Windows are you running?
Have you used Bitlocker on your tablet before?
Are you the only one that has owned this tablet?
Did you by chance make a recovery USB drive when you first setup your tablet?
Can you give me the full model number please?
Okay thank you. Please give me a little time to research this for you.
Does your tablet give you any other recovery options when you restart it?
Do you have your important data backed up?
Do you have a keyboard attached?
Still with me?
Okay no problem, you can get back to me when you have time. When you have a chance, try starting the tablet in recovery mode. Do that by powering it down, then power it back up and tap the F9 key about once per second. If you don't have a keyboard, power it down then power it back up by holding down the power and volume up key at the same time.