Recovery after losing wallet.dat and formatting hard disk I have received the bitcoin way back in 2013 in Bitcoin Core. At that time I don't know about the importance of wallet.dat - I have formatted my hard disk and install Bitcoin Core again in 2017 but there it didn't show my Bitcoin in my balance. I have my Bitcoin Key.
I meant &quot;Bitcoin Key&quot; is my Public Key on which I got my bitcoin. Is there any other way to get my Bitcoin back if I didn't get my original wallet.dat of Bitcoin Core?
How can I get my bitcoin back?
How can I get to know my Private Key?
Your money is lost without at least one of

a backup of important data from the hard disk before it was formatted
a backup of the wallet.dat file
a note of the private key

There is no way to recover the private key from other information. If there was, Bitcoin would be completely unsafe and unusable.