I changed the battery in my laptop

Nice to meet you, *****!
Are you sure you didn't set up Recovery Key upon purchase, sir?

Got you, what Windows do you have?

Got it.

I see, is your computer connected to Microsoft account?

Alright, got you, sir.

That's okay, we'll try working around it. When you first got the computer, did you already have the Windows 10 installed on it?

Got you, do you remember if it already had Windows 10?

Got it, so you use Office frequently, right?

In this case, you do have a Microsoft account, sir. Do you have any other emails besides *****@gmail.com ?

Are you logged into one of your Office programs on another device, maybe your phone? That way, you can check what account you're signed into.

Sure, no problem! Do you use some of the programs on your phone?

Alright, got it.

That's right, I'll check it on the website, then.
Okay, I can see that there's a Microsoft account under this email - *****@gmail.com
In case you forgot the password, we can reset it by sending the security code to the email above. Are you logged into this email, sir? Can you view the inbox messages?

Very good!

I understand, here's the deal. As you've found, if your PC meets certain hardware requirements, Windows 10 Home will provide limited support for some BitLocker features under the name "Device encryption" as opposed to full BitLocker.
Some Dell system models that ship with Windows 10 Home ship with BitLocker "pre-staged", i.e. technically the C drive is encrypted, but BitLocker is suspended, so it behaves as a normal partition. The reason is that at this point, the user hasn't backed up a Recovery Key, so enabling encryption would be unsafe. If however you choose to link your Windows account to your Microsoft account, then your Recovery Key is backed up to your Microsoft account in the cloud and BitLocker is fully enabled - which happens instantaneously because again, technically the drive was already encrypted in advance, so at this point BitLocker just needs to remove the plaintext key that was allowing the encryption to operate in suspended mode.
Unfortunately, the users aren't informed about any of this. They're not told that their drive is encrypted, where to get their Recovery Key if they ever need it, or even that there's a Recovery Key in the first place. That's why this issue is so hard to solve, because many people didn't know the even had the Recovery Key ready.
No problem, we'll reset the password!

To reset the password, please follow the instructions below:

1. Visit the Microsoft password recovery page by this link below:
   https://account.live.com/ResetPassword.aspx
2. Enter the email address you used to create your Microsoft account - *****@gmail.com and click "Next".
3. Select "Email *****@gmail.com" option and click "Get code".
4. Paste or type the code you received and select Next. On the next page, you will be offered to create a new password. Type your new password and select Next.

Great work!
Please follow this link below and check if you can see a recovery key there:
https://account.microsoft.com/devices/recoverykey

Do you see a date?

Ok, in this case, try the first one first, sir.

I know, sorry about that L
Take your time, and let me know how it goes, please!

Is it connected to a charger?
Is this the screen you see, sir?

Okay, can you try following this link, please?

Hmm, I see. Sometimes it can shut off due to inactivity, make sure you're typing the code or touching the touchpad from time to time.

I see, what portion of the code are you able to enter, sir?

Please note that the bitlocker key has two parts - the identifier which you will see as part of the name when you save that as a file - this has letters and numbers. The key itself is in the file and only has numbers.

Do you have two fields in which you have to enter the information?

I see, so when you enter the numbers is stops midway, not letting you type it out fully?
Ok, sure.

Great work, sir! Let's give it some time to reboot.

Me as well, fingers crossed!

So happy to hear that! Are you able to browse the computer normally now?

Okay, let's wait, then! Just to be sure everything is set up :)

:)