Hi
I created a bitcoin wallet once to pay for a service from a site, but i never bought the service and kept the bitcoins. I also very shortly did some mining.
And i changed OS a few times since so i have no files what so ever form then.
So if i don't have a wallet.dat file i have lost that wallet for good ?
//Brian
However, sometimes you forget or misplace your wallet password. This is a bad thing Unless the password is recovered, you have no way to access any Bitcoin or alt-coin funds stored in that wallet. That money is lost forever. At today's exchange rate, that might be a lot of money and your wallet.dat has a key that allows you to use your bitcoins. Without that key, your bitcoins will never be able to be accessed. They will never be put back in a newly minted block because the system won't ever know that the coins are lost. So take special care of your Bitcoin wallet because if you lose it your coins are gone forever