Thank you for the reply!
bitcoin.dat file => maybe, it could *potentially* be your wallet, a .dat extension could also mean it's a wallet that has been generated using bitcoin core.
If it is so, could you please tell how I can use it or where I can read about it? It isn't available for choosing in the attempt to open existing wallet. And all the search keeps pointing me to the wallet.dat file (damn these too smart search engines)
password > only usefull *if* it's the pasword from your bitcoin.dat. IF it's a private key, it *could* be the private key of one of your addresses... It would be even better if it were a master private key. Electrum's master private key starts with xprv. Could you tell us what's the first letter and how many characters this password has?
It is 34 characters long and starts with digits '14'.
Usually, electrum's default wallet is called "default_wallet", There are a couple things you can try:
1) find out wether it's an ascii file, or not (in linux, just type "file bitcoin.dat".
2) you can try to open a copy of the .dat-file using notepad++
3) you can install bitcoin core, rename bitcoin.dat to wallet.dat and place it in the default directory (~/.bitcoin on a linux box), then start core and look in the debug.log to check if the wallet was valid
4) you can rename a copy of the bitcoin.dat to default_wallet and see if you can open it with electrum (altough i doubt it'll work).
5) you can use db_dump to see if it's a berkelydb dbfile
34 characters starting with 14 doesn't sound like a standard private key generated with electrum, sorry...