AS SOON AS YOU HAVE YOUR COINS IN A WALLET - BACK THAT WALLET.DAT UP!! copy - paste - done! (and save yourself some grey hairs)
NO! You backup the wallet BEFORE you add funds to it, but AFTER you have your receive address(es) that you will be using, and AFTER you've encrypted the wallet. You test your wallet beforehand, too!
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[edit:
**NOTE: The following misses "change address" cases, see discussion on the next thread Page #204**; it also misses saving other data that I don't consider critical. Also, I never send to the initial address created automatically in a wallet.]
This is how you should do it:
1. Start a new wallet.
2. Add a bunch of
receive addresses, (like 20, more than you think you need for a loong time.)
3. Download blockchain.
4. Encrypt wallet.
5.
MAKE A BACKUP.5.5 Optional: Make additional backups as needed and store in safe places.
6. Test wallet by receiving a small amount, ( < 0.11 UNO.)
6.5 Test wallet by sending that amount.
7.0 Optional for long-term wallet. (Ignore this step for your petty cash hot wallet(s).): Create a list of the receive addresses, so you can send to them. List must have addresses perfectly copied - no errors!
7.1 Optional for long-term wallet. (Ignore this step for your petty cash hot wallet(s).): Take wallet completely offline. {Programs/Roaming/Unobtanium} move all directories if you know what you are doing! Your cold storage wallet doesn't have to be online for the blockchain to know those addresses are receiving additional funds while it is offline. Just check the blockchain, not your cold storage wallet, to verify you have the funds. Worst case is you only need the private keys on your backed-up wallet.dat file. (Also make sure you never get confused which wallet.dat goes to which wallet, and don't overwrite them, etc.)
8. Optional, but mandatory if applicable:
If you EVER add a single new receive address or change the passphrase or de-encrypt,
you need new backups.9. Send funds to existing, backed-up receive addresses, and enjoy your Unobtanium!!!