So if i need to re-install bitcoincore to a different machine because something hapened to my original bitcoin core ...blackchain and all...
i would be praying i have the wallet.dat and then i would copy that file over to the new installation roaming data folder and bob is my uncle?
what do i need to private keys for though?
You can also do a deep scan of your drive. If you only did a quick-format then its possible to look for keys on the drive on a low-level.
To be safe, make a backup copy of the entire drive, preferably an image.
Then scan the image for possbile wallet.dat files or private keys.
You can do this with a tool call pywallet, you can get it from here: https://github.com/jackjack-jj/pywallet
Good luck!
/KX