client – Triying to help grandpa recover his bitcoins

Back in 2013 my grandfather bought BTC. Wallet.dat file was lost most likely due to pc formatting. He would like to recover his wallet or bitcoins or whatever is possible I don’t understand much about this topic.

I don’t know the details, but here is all I know:

  • The supposed date of transaction
  • Wallet was most likely created using Bitcoin-qt
  • I have a snapshot of the transaction made back in 2013 where his
    public address appears
  • I have access to the same laptop supposedly used to create the wallet
  • Laptop was probably formatted at some point
  • I found a file I don’t know what it is that weighs around 6mb, and
    consists of only Alphanumeric strings and a headers for Msftedit
    5.41.21.2510 (copy paste?)
  • Searching laptop does not yield any wallet.dat file but lots of
    bitcoin related files

Using a file recovery tool is a last resort due to the laptop being formatted (is that word correct?) part and I just don’t want to go there yet.

He is very cautious (except for not backing up wallet.dat lol) and that weird file is stored in a folder named BITCOIN along with a file holding the voucher of his transaction so even if it is not the wallet it should be related to bitcoin.

1 Does anybody know what could be done?
2 Does any body know what that weird file is?

I created a wallet with Bitcoin Core to see what the creation process is and there was a message stating that if the wallet was being created from a backup file then the security phrase would be the same for that backedup wallet. This hints that there is a way of restoring backup files but I didn’t come across it.

3 Would that recovery process help? What file do I need?

I would very much appreciate your help guys, thanks in advance
Alvaro