Bitcoin Forum

Bitcoin => Bitcoin Technical Support => Topic started by: bitfin on November 07, 2017, 03:41:26 PM



Title: Need help / coins lost?
Post by: bitfin on November 07, 2017, 03:41:26 PM
Hi,

i am a total noob and tried to download bitcoin core and receive some coins...

Problem now is: My laptop to small for bitcoin core. But i already ordered coin to my wallet or whatever it is called.

Problem is that i will never receive these coins that were sent to me because my bitcoin core installation will never get "up to date". Blockchain too long. What can i do now?

I need a really easy step by step help what to do, because this is too diff to me atm.



Title: Re: Need help / coins lost?
Post by: xdrpx on November 07, 2017, 04:48:05 PM
If you do not have the resources to synchronize the bitcoin blockchain, your other option would be to dump your private keys from Bitcoin GUI (Bitcoin QT) and then sweep or import them into an SPV wallet like Electrum.

In your Bitcoin QT client open up the debug window and navigate to the console and follow the instuctions below:

Code:
Before you do any of these, go to your source directory of your Bitcoin blockchain and backup everything. Backup your wallet.dat file (this is very important) and keep this safe.

Type these in your console:  

1) walletpassphrase your-wallet-passphrase 300  (What this does is it'll decrypt your wallet if you have a passcode set for 300 seconds)

2) dumpprivkey <your bitcoin address> (This will give you the private key for the address on which you're receiving funds)

Important: NEVER reveal this private key to anyone else, or else you'll risk losing your funds.


Now download electrum from https://electrum.org/ (Verify the signatures, you'll find guides to do it on the forum)

Code:

1) Open up electrum and select Auto-connect to server.
2) Click standard wallet
3) Click use public or private keys
4) Paste your private keys and it'll create a master spending wallet

Note: Your electrum wallet here will not have a seed, and I highly recommend you to make a seed based wallet later by sending your funds from your current electrum wallet to another wallet which is seed based.

Now once you do this you'll see your fund in electrum, but make sure you always create a Seed based wallet in electrum as this one is safest and easier to note down on a piece of paper and to restore at a later time rather than having to note down your private key.

There's also a very detaild and safe guide over here for paranoid users if you need to do it: https://en.bitcoin.it/wiki/Safely_Transfer_Bitcoin_from_a_wallet.dat_File_to_Anywhere,_Using_Air-Gapped_Offline_System,_Bitcoin_Core,_and_Electrum

Hope this has helped.



Title: Re: Need help / coins lost?
Post by: LoyceV on November 07, 2017, 09:17:31 PM
What xdrpx says seems good to me.

As an alternative, you can still keep using Bitcoin Core in prune mode: instead of 150 GB, it only uses about 3 GB on your laptop. It still needs to download the entire blockchain, so it will still take a while, but after that, you can just use it normally.
To enable pruning, close Bitcoin Core, then restart it with command line option -prune=550
Code:
  -prune=<n>
       Reduce storage requirements by enabling pruning (deleting) of old
       blocks. This allows the pruneblockchain RPC to be called to
       delete specific blocks, and enables automatic pruning of old
       blocks if a target size in MiB is provided. This mode is
       incompatible with -txindex and -rescan. Warning: Reverting this
       setting requires re-downloading the entire blockchain. (default:
       0 = disable pruning blocks, 1 = allow manual pruning via RPC,
       >550 = automatically prune block files to stay under the
       specified target size in MiB)