Sorry ah, you two have answered me, thank you both so ...

Hello, this is it, the synchronization is complete, and it worked. I recovered the contents of my wallet, without having to search. Thank you very much for your help. You are the only one to have answered. Good day and happy holidays.

Ok thank you very much. I did a "cut and paste" File "wallet.dat" only on a USB key. Is it not necessary to copy other files in C:\Users\VINCENT\AppData\Roaming\Bitcoin as "blocks" "chainstate" File, "database", "peerst.dat", "db", "debug"?

Ok, I specify that all my past transactions appear in the "Transactions" of the new version Bitcoin CORE window, but the money is still 0, since we are still in the process of "re-indexing of the blocks on the disk ".

Ok, thank you. I did not backup my wallet, unfortunately. But I have not deleted. I do not know how to find my wallet in files on my computer. Before, when I wanted to access my wallet, it was enough to open the application. And now it does not want to open. There an hour before re-index blocks on the disk, the latest transactions in the old wallet will be displayed. I do not know how to make a backup now that I no longer have access to the previous bitcoin-0.8.3-win32 setup?

Thank you very much for your help. He said that my wallet is out of sync. It says "re-indexing of the blocks on the disk."
I hope he will find the contents of my wallet.?

I can not start my wallet bitcoin-0.8.3. An error message appears on my screen: system error: database 1/0 error. What can I do?