Wallet.dat file - where is it in Copay, Exodus, Electrum & Jaxx in Windows? I would like to make sure thata I securely encrypt it for protection & to copy it somewhere else for a backup.
You should just follow the step-by-step from each wallet to backup them. Usually they will give you a seed phrase that can be used to restore your wallet in case of any problem.
Electrum: save your backup seed if you are using a HD wallet or backup the wallet file inside the Electrum folder at %APPDATA%\Electrum\wallets
Copay, Jaxx and Exodus: save your backup seed.
I've already backed up the wallets and saved the back up seed but I would also like to encrypt the wallet again my own way just to be safer from someone trying to steal and hack my wallet.
Electrum - ok, that one is easy to find the wallet file but not sure where to find it for Copay, Jaxx & Exodus.
As I said, for most wallets, you should backup your seed as it's explained in every software and not necessarily copy a file.
Copay: Go to Settings -> Wallets -> Choose your wallet -> More Options -> Export Wallet -> File/Text -> Set up a password -> Download.
Jaxx: Click the Menu icon at the top right -> Tools -> Backup Wallet.
Exodus: Go to the "Backup" screen and just follow the wizard.