Helo . inn wallet bitcore qt windows. what should be saved for recovery wallet? such as the fear of someday I will reinstall windows and so on.
what should I keep and how to restore it
Set a passphrase for your Wallet, then save the wallet.dat - if you are on Windows that file is in your User home directory C:\Users\\AppData\Local\Bitcore.(I not sure, if it is in the Local dir or Roaming, but one of those)
If you ever reinstall your system, to recovery your wallet just replace the wallet.dat in your new installation.
HODL!