Computer crashed, total reinstallation. Have wallet.dat but not private key

My computer crashed and I was using the Bitcoin Core/QT client (they're the same right)? I thought I had my public and private keys saved, but those keys are from my old Armory wallet. I don't think I swept them to Bitcoin core, but I still used those keys for encryption/decryption. I was able to retrieve the wallet.dat file from the oldwindows data that is backed up on my computer, but I was wondering if I could retrieve my private key from the dat. file and how. Or if that isn't necessary, how should I go about reinstalling the bitcoin client so that I will have my coin back? I appreciate your help.

Johnnycrash

Posted 2018-02-12T19:16:26.567

Reputation: 3

I do have access to old receiving and sending addresses. As of yet I haven't reinstalled a fresh Bitcoin Core client. It will take generally a week or so to sync/install. I don't know if the oldwindows backup is going to slow my comp down down more or not. Seems like the repair shop would've saved oldwindows to an external drive. Anyway, one site told me to install the bitcoin core client, don't start it until I delete the newly created wallet.dat and replace the new dat file with my old one. Then restart the client? Rescan the blockchain? I would feel much better if I had the private key. – Johnnycrash – 2018-02-12T19:53:41.803

bitcoin is significantly slowing down your PC only when it is syncing the blockchain. But if you have a copy, it is perfectly ok to restore from backup. If you have old wallet.dat, just replace it, that file contains your private keys. You can extract privkeys with the command line interface in bitcoin-QT, see here: https://bitcoin.stackexchange.com/questions/4203/how-can-i-export-the-private-key-for-an-address-from-the-satoshi-client - let us know, how it goes.

– pebwindkraft – 2018-02-13T08:51:14.510

Answers

As long as you have wallet.dat file and encryption key so you have nothing to worry about.

You can reinstall Bitcoin-core and move your wallet.dat file to bitcoin directory (./bitcoin on Linux) then you will be able to use it like nothing happened.

To get your private keys from wallet.dat you could run in your terminal

bitcoin-cli walletpassphrase "PasswordHere" 600
bitcoin-cli dumpwallet "txtfile_keysFile_path.txt"

All your private keys will be stored in that path.

Adam

Posted 2018-02-12T19:16:26.567

Reputation: 3 215

Thanks for the help. So using Windows 10, to restore the wallet.dat to the new wallet I would install the Bitcoin-Core client but not run it, switch the wallet.dat files, and then run it? Would it be easier to go into the command prompt and get the private keys? – Johnnycrash – 2018-02-13T03:06:52.477

Yeah switch the files and run it. it doesn't really matter if you do that through command prompt or GUI since you need to install bitcoin-core anyway. – Adam – 2018-02-13T11:35:20.663

It sounds like I have everything I need to get my wallet back up and running. Obviously it's going to take some time to sync the blockchain, but I feel better now that I know what steps to take. I really appreciate all the assistance. – Johnnycrash – 2018-02-13T18:01:56.023

I just have a couple quick questions. Is it necessary to delete the new wallet.dat after switching them? Also, it shouldn't do any harm to my wallet by running the command prompt to retrieve the keys, right? I would like to have the keys in case there's any trouble switching the wallet.dat files. Thanks again. – Johnnycrash – 2018-02-13T18:18:50.423

doesn't really matter as you have no funds with the new wallet. No, it will never harm anything. Just keep a copy of your wallet.dat file somewhere else and set a copy in new bitcoin directory and you can try whatever you want. Don't forget to mark the answer if that helped. – Adam – 2018-02-13T20:32:20.753

Yeah this has definitely helped ease the apprehension I had about restoring my coin. I have one more question: Do I switch the wallet.dat file as soon as I install Bitcoin-Core, before syncing the blockchain, or do I have to sync the blockchain, switch the .dat files, and then re-sync? Thanks. – Johnnycrash – 2018-02-13T22:45:13.590

Doesn't really matter. – Adam – 2018-02-13T23:39:40.910

I should be good from here. Thanks for everything. – Johnnycrash – 2018-02-14T17:23:13.683

Ok. I'm syncing the blockchain, which will take a while. I wasn't sure if I had to download the chain before or after installing the Bitcoin client. I didn't see a wallet.dat in >appdata/roaming/bitcoin< to switch after simply installing the new wallet. So I'm syncing, and then I'll switch the new wallet.dat with the old wallet.dat. At that point will I have to simply restart the client, or do I need to resync the chain? What steps would I take to do that if so? – Johnnycrash – 2018-02-14T22:14:36.787

I didn't have any luck getting the keys using the command prompt. I haven't set a passphrase or pw, so I just used the second command-line. It didn't recognize it as a valid command. Were you saying to use that in the Bitcoin console? I was trying to do it from DOS. Many thanks. – Johnnycrash – 2018-02-14T22:23:58.653

try on bitcoin console with removing bitcoin-cli – Adam – 2018-02-14T22:55:44.473

Since I was installing a fresh copy of Bitcoin-qt and had to sync the blockchain from scratch, I simply swapped the wallet.dat files. There is no need for a forced rescan or to go into the console at all if you do it this way. 1st find your old wallet.dat. Install and start syncing the new wallet. Once it starts syncing, go to C:\Users\YourUserName\Appdata\Roaming\Bitcoin and swap the new wallet.dat with the one you want to use. Rename the new wallet.dat "backup wallet data" and use your old wallet.dat. I did it while it was syncing but before the date I made transactions, so just do it early. – Johnnycrash – 2018-03-08T01:46:08.093

Just switch your old wallet.dat with the newly created one.

When my computer and Bitcoin-QT crashed, I retrieved and backed up the old data. Geeksquad can do this part for you if need be but it isn't difficult. Once I had the data and a fresh install, I went to retrieve the wallet.dat from my old computer files at C:user/username/appdata/roaming/bitcoin. I backed that up and made copies of the wallet.dat file. Next, I installed a new Bitcoin-QT client and started syncing the blockchain from scratch. Shortly after beginning the process of syncing, I swapped the newly created Bitcoin wallet.dat with the one that had coin on it. It's probably best to rename the new wallet.dat "backup wallet data" instead of deleting it, but it doesn't matter. It just matters that the wallet.dat that you want to use is the only "wallet.dat" file in the folder or it won't know which one to read. Once the chain was done, my coin showed up.

Johnnycrash

Posted 2018-02-12T19:16:26.567

Reputation: 3