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I don't understand how it can be fake, it was in my brother's pc who didn't understand anything about computers and moreover it's from 2009 also the date of the last modification (of the wallet.dat)
If he didn't understand computers how / why would he be mining
BTC within it's 1st 6 months of existence?
And if he didn't understand computers, and he was mining it's possible he was doing it wrong.
Just looking around all the blocks that were mined on that day the times shown in the GUI don't match up with any blocks.
At a guess, if he was mining he generated a block that was not accepted and then kept mining on top of that so the entire chain was not accepted.
They should not have been accepted..