Bitcoin Forum

 I am worried about losing my bitcoins on my computer, so I made .dat file and save it on my computer (safe place ).

1) if I made other copy of a wallet.dat file can use copy file to recover the lost bitcoins?

2) if number 1 right How can save my wallet and backup using one .dat file?

As long as you have available copy of your wallet, you have an access to all the funds on it. From personal experience i can verify that if you have saved wallet.dat file, you can install new client, replace the existing wallet.dat on pc (newly installed) with backed up, wait a few days/week for blockchain to download and your coins will be there. As for saving, just copy the file to same safe place. You can additionally encrypt it. Check this: https://bitcoin.org/en/secure-your-wallet

EDIT: you can test this if you have second pc - do the steps from above on second pc and it should be fine. This way you will be 100% sure that you're on a safe side.

When you have the .dat file, it's good enough to recover your wallet from any newly installed computer.

You can save you .dat anywhere as you like. Normally I save the zipped .dat file in my computer and also send it to 2 different email box. Thus I think the money should be 100% secure. Take care of the passphrase by the way.

You can use the wallet.dat file to recover your address, Bitcoins however are stored on the Blockchain, so if somebody else moved them they won't be there any more.

Assuming that you are talking about Bitcoin Core, which version did you create your wallet at? If its recent, then it would probably have a HD wallet. You can verify this by opening up your client and if there is a HD symbol on the lower right, you have a HD wallet. This means that the addresses in the wallet is generated from a string of letters and only one backup is enough*.

If its not a HD wallet, you have to back it up every 100 transactions, every single copy has to be replaced.

* Unless you either encrypt your wallet or change your password. You will need to back it up again if you do.

I'm running Electrum and I know that is a HD wallet.  What does that mean - back it up once? If you say buy or sell using that wallet, shouldn't you do continuous backups of your wallet.dat file. 

The procedure for using a HD wallet for Electrum is completely different in contrast to Bitcoin Core. For Electrum, you are only supposed to back up the seeds and not the wallet file. The opposite is true for Bitcoin Core.

That used to be true in the past and for Core wallets that aren't created with HD; you are expected to back up every 100 transactions.

For the love of god please encrypt the wallet.dat with a password and most importantly...DONT FORGET THE PASSWORD!!!

I have 15.5 BTC in the ether somewhere protected by a 37 character password. i was lucky to find a big chunk i mined in 2012/13.

Maybe get a copy unencrypted and encrypted just in case.

wallet.dat file keeps only the address or your wallet. other information regarding mining and staking are in other files. So you should save complete folder in c:/programfile/appsdata/roaming/CoinName .

No. If you encrypt/unencrypt the wallet file, the keypool will be refreshed or the HD seed will be changed.

Either you use a wallet.dat unencrypted or encrypted with the same passphrase as those in your backups.

I am using Electrum desktop windows wallet which lite and secure, very easy to use. I dont have to save wallet.dat file just the seed key i have to keep safe and that is enough. When ever and where ever i want i can just download the wallet software and install it and insert the seedkey and their my wallet is up with latest update of my wallet details. So easy to use and more secure just we have to secure the seedkey that is enough

Is this specific to Electrum? I used Core. That may be the difference.

Yes, with copies you are safe, but you should keep something in mind.

When you spend BTC, let's say you have 1 BTC and send 0.25 BTC out.
The remaining 0.75 BTC is sent to another address of the wallet, that can be generated on the go.
It means that you have 0.75 BTC in this wallet.dat

Now if you erase it and try to load a copy, you'll find 0 BTC, not 0.75.
Why ? Because the key to the 0.75 was ONLY on that first wallet.dat, since the address was just generated.

So be careful and you should make backups of your wallet.dat after each outgoing transaction, just to be sure to keep the change. :D

I thought encrypting wallet is simply hiding original data, good to know so I don't make stupid mistakes in the future.
is this encrypting method as in BIP39 Passphrase? just like what's on iancoleman BIP39 Mnemonic Code Converter?
if so, yeah I guess it would generate a whole different set of addresses for different passphrases
if I started with unencrypted wallet and receive some coins, then I decided to encrypt my wallet
would that mean I will lose (cannot see) those coins that I received earlier when it was unencrypted?

Yup. Electrum's seeds never change, encrypting and decrypting the wallet files will not make a single difference.
Nope. It refreshes the keypool.
No. Core doesn't adopt BIP39 mnemoric.
There's a string of letters generated for your Bitcoin Core HD wallet. When you encrypt the wallet, Core dumps out all the used addresses and generate a new string of letter to generate new addresses in the future.

Of course you can still access the old addresses. But you cannot access any future addresses generated by the encrypted wallet.dat if you're going to use the old unencrypted wallet.dat as backup.

at least twice encrypt, first encrypt by bitcoin client, second compress by winrar or other compress software, a strong password is very important.