HI, in 2 years Imported my brain wallet in electrum, I imported the private key of my brain wallet, but I generated one new address and receive bitcoins in one new address, I lost my computer and not made one backup of this new wallet with the new address generated only have my private key of my brain wallet, I imported again in electrum but not imported the new address before of lost my computer, I have any chance of recovery the private key of this address then was generated in wallet of I imported the my private key of my brain wallet? I have the address of new generated address then have my bitcoins and the address and private key of my brain wallet but not have the new private key of my new address then have the my bitcoins, thank you.
Electrum has 2 kinds of wallets:
1) an HD wallet, this wallet basically uses an xprv (a master private key) to derive subkeys (private keys), the subkey can be used to derive a public key, and the hash of the public key is the address. An unlimited amount of subkeys can be generated, each time one of your addresses gets funded, a new private key/public key/address gets derived, each time you generate a new transaction, a new change address gets derived.
When you generate a new HD wallet, you are presented with a recovery seed. This is basically a phrase consisting of x words. If you restore your wallet, and enter the recovery seed, electrum can regenerate the old xprv, and derive all old private keys...
2) you can also generate a wallet by importing one or more private keys. Such a wallet cannot generate new addresses. If you import a private key from, for example, a brain wallet, the address generated by hashing the public key belonging to the private key you imported will be the only address that is ever monitored by your wallet.
In reality, only 2 things could have happened:
1) you generated a new HD wallet, and unwillingly swept your brain wallet. By sweeping the brain wallet, a new transaction was generated that spent all unspent outputs funding your brain wallet in order to fund an address belonging to your HD wallet
2) you generated a non-hd wallet, in which case the unspent outputs shouldn't have moved. If you remember all private keys you imported during the wallet creation, you should have access to your balance
So, in order to regain access to your funds, you need:
1) either the wallet seed phrase, if you generated a hd wallet and swept the brain wallet
2) or all private keys you imported during wallet generation... If you imported multiple private keys, it *is* possible you need all of them to regain access to your funds
3) you could try to find the old wallet file, it'll either have the xprv, or the private keys...