Bitcoin Forum

Ok, so my computer crashed.  I have a backup of my wallet, and I put it on a new computer.  However, I generated a couple of new addresses since my last backup and the backup doesn't have a record of them.  I'm downloading the blockchain now, but I don't know how to import my addresses into my new bitcoin client so it can update my balances.  How do I do this?

You can't.

Anyway, I know that the wallet already have 100 adresses at start.
So if you haven't create any more addresses over 100, you should find all of them.

When I backed up the wallet I had created three addresses.  Those were present.  But I created new addresses (10 or so) after the backup.  How do I "re-import" them?  I know what they are, is there a method to re-attach them to the newly imported wallet?

And I've heard that if you have someone's private key, then you can spend their bitcoins.  I have my private key and my public keys.  How do I access them?

Some of the dev versions of bitcoind can import and export keys.

Since you know the private key, the easiest thing to do is import them to a wallet at blockchain.info

The wallet should have those addresses in its buffer. Which means that if you click on "generate new address", the new addresses you'll get are the ones you had before. What they won't have is the label, which you can add.

Do note however that change addresses, generated when you send bitcoins, also count towards the 100 addresses buffer.

You should be able to see the coins in your balance and spend them even without re-generating the addresses.

I've never actually tried this before so reports on your progress will be welcome.

They're already in his wallet, no need to import anything.

Ok, so I generated new addresses, and as i was told, the addresses match the old addresses.  The blockchain is taking a while to download (computer is slow), but transactions are starting to come through.  My mind is much at ease.

Thanks for your help.

Your backed up wallet has 100 "pre-made" addresses that it hadn't used yet.  When you made your 10 new addresses after backing up, you got the first 10 of those pre-made addresses, and you'll get the same after restoring the wallet.

If you made transactions since backing up, the change may have gone to one of the addresses which you got as a 'new' address from before the crash, so that can get a little confusing - what used to be a 'new' address may now be a 'change' address, and vice versa.  But you shouldn't lose any coins because of it.