I was able to make a BTX deposit on cryptopia just now, such a dick move...
what should i say that i had to format pc and didn't made a backup of wallet?
my address has about 150 btx but they are lost forever
Damn, that is sad

You really should always have a backup copy of all your local wallet, on a external hard drive, or memory stick.
So in case we need to backup its enough to keep the file wallet.dat in external hard drive and to replace that file if we make a new wallet right?