1/ Is it possible that the first programme to create bitcoin pas not bitcoin ( core, qt or what ever) but Windows itself? With an internal program like a dll or something like that?
So there where no wallet.dat in this case i imagine but an other form of file to stock datas.
It was saving the information in a
wallet.dat file if we're talking about the same version (0.1). Here, try it yourself:
bitcoin-0.1.0.rar. Not sure that I've fully understood your question, though; you tell me.
2/ Is it possible that the first hashes were web pages but not only? Was it possible to hash some lusic or some pictures etc to create bitcoins?
To what hashes are you referring in? To addresses' or to mining's hashes? In SHA256, it is possible to hash anything that can be represented in bits and is not longer than 2
64 - 1 bits.
3/Was the B of bitcoin the first symbol uses to figure it? Was it possible to use an other like a square or something else?
I think the first symbol was ฿. That was the icon in v0.1.0: