If you don't know your wallet passphrase, then trying to recover your coins from Bitcoin Core will be quite difficult. There is no way to recover the private keys from an encrypted wallet.dat file without the passphrase.
You'll need your wallet.dat file and to use a script like btcrecover (https://github.com/gurnec/btcrecover) to be able to try and recover the passphrase.
Topic: How to recover btc after windows reinstall - page 2. (Read 6680 times)
what files are required to recover your BTC? I am having same issue with my bitcoin core and did not back up the private passkey.
I suggest looking into Disk Drill by Cleverfiles, I have successfully used that tool to recover files deleted and from drives that have been re-partitioned. Wallet files are small enough you can recover anything the approximate right size you find for free with the trial version.
For clarity, in this recovery attempt you are only reading from the drive in question correct? Not trying to run or write anything to the drive anymore? The less you do to the drive the better.
You might also consider talking to someone like "Dave Bitcoin" (you can find him easily) who has many years experience helping people recover wallets for a 20% bounty (only on the ones he is successful on).
For clarity, in this recovery attempt you are only reading from the drive in question correct? Not trying to run or write anything to the drive anymore? The less you do to the drive the better.
You might also consider talking to someone like "Dave Bitcoin" (you can find him easily) who has many years experience helping people recover wallets for a 20% bounty (only on the ones he is successful on).
Just in case anything messes up can I download and run electrum with core still running and console open etc?
Yes, running electrum at the same time as core shouldn't be a problem.
Before importing your key into electrum I recommend searching for its associated Bitcoin address here. If blockchain.info shows no funds in that address then there's not much point importing it into electrum.
https://blockchain.info/
I'm not very familiar with Bitcoin core, there are people here much better qualified than me to answer questions about it.
However, i think there's some kind of bug affecting the salvagewallet command, and that creates BAK files. I don't know how to fix the problem though.
https://github.com/bitcoin/bitcoin/issues/7463
Just in case anything messes up can I download and run electrum with core still running and console open etc?
Yes, running electrum at the same time as core shouldn't be a problem.
Before importing your key into electrum I recommend searching for its associated Bitcoin address here. If blockchain.info shows no funds in that address then there's not much point importing it into electrum.
https://blockchain.info/
Just in case anything messes up can I download and run electrum with core still running and console open etc?
Yes, running electrum at the same time as core shouldn't be a problem.
Before importing your key into electrum I recommend searching for its associated Bitcoin address here. If blockchain.info shows no funds in that address then there's not much point importing it into electrum.
https://blockchain.info/
Just in case anything messes up can I download and run electrum with core still running and console open etc?
Just ran dumprivkey in console with the one receiving address and it has shown a key beginning with k, would that be anything of interest?.
That's a Private Key in WIF Compressed format. You can import or sweep it into a wallet like electrum to spend any coins associated with it. These are the instructions explaining how to do it.
http://docs.electrum.org/en/latest/faq.html#can-i-import-private-keys-from-other-bitcoin-clients
http://docs.electrum.org/en/latest/faq.html#can-i-sweep-private-keys-from-other-bitcoin-clients
Sweeping's probably better than importing, but it doesn't really matter which technique you use.
You can download electrum from here.
https://electrum.org/#download
When we need to recover btc after windows reinstall,Electrum wallet generation seeds give you a 12 word phrase of password (order is important).when we clean and reinstall we put this phrase we got it our previous wallet. 
I know it's a big ask but could anyone post a guide on installing pywallet from scratch for a novice computer user including screenshots?.
It seems to me that a lot of people could do with a guide that is easy to follow and once one is posted it could help a lot of people, based on all the posts relating to corrupt wallets etc.
It seems to me that a lot of people could do with a guide that is easy to follow and once one is posted it could help a lot of people, based on all the posts relating to corrupt wallets etc.
I have just copied and pasted the receiving address into blockchain info and it didn't show any coins or transactions to that address 
Is there only one receiving address showing in the window that opens when you click file, then receiving addresses?
If blockchain.info shows an address doesn't contain coins then it's almost certain the address is empty.
Bitcoin core should show all the receiving addresses generated in a wallet.dat file before it has synced. This is what an example receiving addresses window looks like in an unsynced Bitcoin core.
I have just copied and pasted the receiving address into blockchain info and it didn't show any coins or transactions to that address
Is there only one receiving address showing in the window that opens when you click file, then receiving addresses?
If blockchain.info shows an address doesn't contain coins then it's almost certain the address is empty.
I have just copied and pasted the receiving address into blockchain info and it didn't show any coins or transactions to that address
Is there only one receiving address showing in the window that opens when you click file, then receiving addresses?
If blockchain.info shows an address doesn't contain coins then it's almost certain the address is empty.
I have just copied and pasted the receiving address into blockchain info and it didn't show any coins or transactions to that address
Trouble is that it by default places the Bitcoin folder in c which is 250GB and there is only 70GB of space left. I copied the second wallet dat file onto the same usb stick as the first i recovered and had to name it differently.
If you don't have enough hard drive space try extracting your private keys from Bitcoin core, installing the electrum wallet, then importing the private keys into it. These instructions explain how to do it.
Search for all the Bitcoin addresses that Bitcoin-QT shows on this website. That site will tell you if an address contains Bitcoins.
http://blockchain.info/
To view the addresses in Bitcoin-QT click "file" in the menu, then click "receiving addresses" in the drop down list that appears.
If blockchain.info shows an address contains coins you can either wait for up to a week for Bitcoin-QT to sync, or use a different wallet to spend them immediately.
If you want fast access to your Bitcoins you need to extract their private keys from Bitcoin-QT, then import those private keys into alternative wallet software like electrum.
To extract the private keys click "help" in the Bitcoin-QT menu, then click "debug window" in the drop down list that appears.
Click the tab labelled "console" in the debug window that appears.
Type dumpprivkey, then a space, then your Bitcoin address in the text box at the bottom of the console window. This is an example.
dumpprivkey 1Cgu5PQyTYrZn4VtAs2T1FHf1ayXVYHNDt
Afterwards press your enter key to view the private key for your Bitcoin address. There's an example private key (L4RY4tv1Qpr4FVxtSLnr7vJiUCvk7A7C2Cd6M7QSU2BkRtj9vhnd) shown in the screenshot.
Copy the private key, then download and install the electrum wallet from here.
https://electrum.org/#download
After installing electrum you can either import or sweep your private keys into it using these instructions.
http://docs.electrum.org/en/latest/faq.html#can-i-import-private-keys-from-other-bitcoin-clients
http://docs.electrum.org/en/latest/faq.html#can-i-sweep-private-keys-from-other-bitcoin-clients
Trouble is that it by default places the Bitcoin folder in c which is 250GB and there is only 70GB of space left. I copied the second wallet dat file onto the same usb stick as the first i recovered and had to name it differently.
I have tried another recovered wallet.dat file and it hasn't crashed. If there are some coins in it, how long would they take to show up. Thanks.
It could take a long time, you have to wait for core to sync before you can see balances.
Check all the addresses that core shows in a block explorer like this one. If an address contains coins the block explorer will immediately tell you.
https://blockchain.info/
Bitcoin.org recommends having 145 GB of spare HD space. Which folder did you rename to wallet.dat2?
By default Bitcoin core looks for a wallet.dat file in a folder named Bitcoin that's inside a hidden folder named appdata.
I have tried another recovered wallet.dat file and it hasn't crashed. If there are some coins in it, how long would they take to show up. Thanks.
It could take a long time, you have to wait for core to sync before you can see balances.
Check all the addresses that core shows in a block explorer like this one. If an address contains coins the block explorer will immediately tell you.
https://blockchain.info/
I have tried another recovered wallet.dat file and it hasn't crashed. If there are some coins in it, how long would they take to show up. Thanks.
It could take a long time, you have to wait for core to sync before you can see balances.
Check all the addresses that core shows in a block explorer like this one. If an address contains coins the block explorer will immediately tell you.
https://blockchain.info/
I have tried another recovered wallet.dat file and it hasn't crashed. If there are some coins in it, how long would they take to show up. Thanks.
Jump to: