Help recovering 2015 wallet.dat

[HelpwithWallet]

Hello,

I have a backup_wallet.dat file from 2015. It was on a laptop using bitcoin core which could not longer sync. So I created a backup and put that file on my new pc running windows 10. I've tried to install the latest bitcoin core program but I get an error when installing.

Error Loading Database
Do you want to rebuild the block database now?
OK/Abort

Both options just close the installer.

Any suggestions on where to go from here? I've read the guides and have only found solutions to people with this error after they have already successfully installed the wallet.

[jackg]

I've read the guides and have only found solutions to people with this error after they have already successfully installed the wallet.

The block database is nothing to do with your wallet file, I don't think there would be an obvious error if the file loaded wrong.

Do you have the last few lines of your debug log just as the error started?
Also if you're not far with the syncing process, you can try to run the program with -reindex and see if that fixes your problems.

[PawGo]

Also if you're not far with the syncing process, you can try to run the program with -reindex and see if that fixes your problems.

Reindex usually works.
What you may also do is to delete the whole database and try to download from the beginning (if you have time...).

Do you still use Bitcoin Core version from 2015 or the latest one?

[HelpwithWallet]

I looked in the bitcoin folder and I did not see a debug log.
Could you explain the -reindex or link to a topic that covers it?

I don't have space on the hard drive to run a full node.
I downloaded bitcoin core v 22.0. I'm not sure what version was on the laptop from 2015, but it was out of date and could not sync.

Here is the error that pops up within 10 seconds of trying to install the bitcoin core wallet.

https://i.imgur.com/t9EAFDP.jpeg

[HelpwithWallet]

Okay I was successfully able to install Bitcoin Core version 19.0.1

However, it is syncing with the network and is 12 years behind. I do not think I have enough space on my hard drive to complete the sync. Last time it took up like 900 GB when I tried a year ago.
https://i.imgur.com/cjWHOuy.jpeg

While it's syncing I looked to see if there was any options in the settings to import my old backup_wallet.dat file and I don't see anything.

[PawGo]

I looked in the bitcoin folder and I did not see a debug log.
Could you explain the -reindex or link to a topic that covers it?

When you launch program as a 'bitcoin-qt.exe', add parameter '-reindex', so at the end you launch

Code:

bitcoin-qt -reindex

-reindex throws away the block chain index and chain state (the database of all unspent transaction outputs), and rebuilds those from scratch. It is exactly like downloading the block chain again from peers, except the blocks already on disk are used.

I don't have space on the hard drive to run a full node.

You may launch it with prune option specified in program (I even think it is enabled by default), so blocks will be downloaded and processed but only a given space on disk will be taken (for example 1GB).
The problem is that if you load wallet which state is before the date of your 'database', wallet will not be opened/functional and redownload of blocks will be needed. If you do not plan to open old wallets but work with only one or create a new one - this is the option for you.

[HelpwithWallet]

I get this error when I try to rename the exe to add -reindex.

https://i.imgur.com/c7yNz9n.jpg

[HelpwithWallet]

I also have a 2nd wallet that is even older (2011), but I have less hope of recovering anything from that than the 2015. The wallet files are all .h or .cpp.

https://i.imgur.com/KVcrmJP.jpg

[RickDeckard]

I also have a 2nd wallet that is even older (2011), but I have less hope of recovering anything from that than the 2015. The wallet files are all .h or .cpp.

Regarding your wallet.cpp file, I'll post a reply from mocacinno that should clear your doubts regarding the file:

A friend has written to me about discovering a wallet from 2011. It's not a wallet.dat etc. but wallet.cpp

I'm curious what this was. There is almost not much information on it later on.
https://github.com/bitcoin/bitcoin/blob/master/src/wallet/wallet.cpp

cpp => c plus plus (c++)
This is basically just bitcoin core's sourcecode... it's not a wallet file, it does not hold private keys or any other personal information, it's just part of the sourcecode, the only thing you can do with it is compile it...

unless your friend has renamed his wallet.dat to wallet.cpp (but that would be a rather big coincidence). If you try to open the file with a text editor, and you can read the code, it's just sourcecode... If you see a bunch of gibberish characters, it might be a renamed wallet.

[HelpwithWallet]

Interesting. That screenshot is just of the files named wallet. All the other files are still in their proper directories. It's just the application is so old it refuses to run. I guess if the wallet was stored in some sort of temp or roaming directory it is long gone then.

[HCP]

If you don't have space to run a full node with all the block data... running a pruned node and working with old wallets is going to be very frustrating!

Every time you want to open an "old wallet" that was last used from outside of the time period that match the blocks still on your disk, you'd need to redownload the entire blockchain again. This can take many hours, if not many days

The ideal solution is a full, unpruned node.

If you absolutely need to run it pruned, then you might want to edit the bitcoin.conf file (or start from the commandline) and pass in the -wallet parameter as many times as necessary to open all of your old wallets at once.

Code:

-wallet=<path>

Specify wallet path to load at startup. Can be used multiple times to load multiple wallets. Path is to a directory containing wallet data and log files. If the path is not absolute, it is interpreted relative to <walletdir>. This only loads existing wallets and does not create new ones. For backwards compatibility this also accepts names of existing top-level data files in <walletdir>. 

For example, if you had the following wallet files:
old_wallet.dat
wallet_2015.dat
my_wallet.dat

You could start Bitcoin Core:

Code:

G:\Bitcoin\bitcoin-qt.exe -wallet=old_wallet.dat -wallet=wallet_2015.dat -wallet=my_wallet.dat

I get this error when I try to rename the exe to add -reindex.

You don't rename the .exe file... you "append" the -reindex parameter to the end of the command... You either need to create a shortcut to the bitcoin-qt.exe and then edit the properties for the shortcut to change the "target" like so:


NOTE: make sure that the path to the bitcoin-qt.exe and the "start in" are relevant to YOUR setup... Based on your screenshot, I would guess instead of C:\Program Files\Bitcoin... it should be G:\Bitcoin for your setup.

Alternatively, just launch it from a "Command Prompt" window (Start, type: cmd)... then enter this command:

Code:

G:\Bitcoin\bitcoin-qt.exe -reindex -wallet=OldWalletFileName.dat -wallet=OtherOldWalletFileName.dat

That'll start up Bitcoin Core GUI, opening your old wallet.dat files... and start the reindexing process... This will likely require downloading and validating the entire blockchain again... but when it's finished, all the old wallet.dat's that you open should be "synced" and ready to use.

[BitMaxz]

Okay I was successfully able to install Bitcoin Core version 19.0.1

However, it is syncing with the network and is 12 years behind. I do not think I have enough space on my hard drive to complete the sync. Last time it took up like 900 GB when I tried a year ago.

While it's syncing I looked to see if there was any options in the settings to import my old backup_wallet.dat file and I don't see anything.

What does the plan do you actually want about your wallet? Do you want to continue using Bitcoin core? Using bitcoin core will download the entire Bitcoin blockchain except if you set it to prune mode but you won't be able to use most of the console commands.

Do you want to withdraw your funds from your wallet?
If that's what you want then you don't need to download the entire blockchain just let it run while syncing and go to console to dump all private keys from your wallet.dat but before you do that you need to import your wallet.dat there is no option on the settings that you can import wallet.dat. Since you mention that you are using Windows 10 OS then you can manually import the wallet.dat under %appdata%/Bitcoin then look for the wallet folder and paste the wallet.dat there. Once it's done you can now open the Bitcoin core wallet and proceed to export the private keys from your wallet.

To export, the private key goto console you can find it on Window>Console or through shortcut CTRL+T.
Then type this

Use this only if you remember that your wallet has a password.

Code:

walletpassphrase yourpassword 200

Then enter this

Code:

dumpwallet C:/mydumpwallet.txt

Now you have a dump wallet with your all private keys next what you need to do is to install Electrum to import them. It doesn't need to download the entire blockchain so you don't need to wait for long after you import all private keys it will sync few a couple of minutes then you're ready to send BTC from your wallet.

Another option is to dump the wallet with pywallet.py it requires python so you will need to install a python in your system.
You can find the tool here https://github.com/jackjack-jj/pywallet

Then for the guide check this post below

- https://bitcointalk.org/index.php?topic=285947.msg55561003#msg55561003

It only dumps or exports the private keys from your wallet.dat file once you are successful in dumping your private keys from your wallet then you can proceed to import it to Electrum. This one should be the best option it doesn't need to download the entire blockchain or wait to be fully synced.

[LoyceV]

Okay I was successfully able to install Bitcoin Core version 19.0.1

Is there a reason you choose a much older version? See the top of this page for 22.0.

I do not think I have enough space on my hard drive to complete the sync. Last time it took up like 900 GB when I tried a year ago.

You must have remembered it wrong, it's currently a bit over 400 GB.

I get this error when I try to rename the exe to add -reindex.

Just in case: you've made several backups of your wallet.dat before messing with it, right? If not: you should do it now.

[impresiones]

Is there any web that could help with this?

[nc50lc]

Is there any web that could help with this?

What do you mean? A customer service representative?
If it's support, he already got the best solutions in this thread, be it 'to export the keys' or 'to fully sync core', they've already got it covered.

It's just OP didn't responded and looks like he prematurely gave up in his last reply:
(I think he doesn't really got a wallet.dat file but the renamed "wallet" source code of Bitcoin Core)

-snip- I guess if the wallet was stored in some sort of temp or roaming directory it is long gone then.

[BitMaxz]

Is there any web that could help with this?

Are you looking for a recovery service?

If your problem is encrypted wallet.dat and you can't remember the passphrase then walletrecoveryservices.com is what you looking for but if your problem is the same as the above then all solution already posted above.