By default, when installing the Nxt/Ardor software as a 'full client' the local wallet automatically finds other remote peers and starts the blockchain download. This process is very secure, since your node re-validates all the transactions during the download.
However, on slow hardware or limited internet connection this process can be very time consuming and could take several days (Nxt) or hours (Ardor). If you are in a hurry, and trust Jelurida to provide a good copy of the blockchain, you can go to the Jelurida homepage www.jelurida.com
and download a copy of the blockchain database.
There are several options:
- is the NXT testnet database used for development and testing (doesn't contain real transactions)
- is the Ardor testnet database used for development and testing (doesn't contain real transactions)
On Windows (when using Nxt mainnet) the blockchain will be downloaded to your "C:\Users\USERNAME\AppData\Roaming\NXT\nxt_db" folder. Make sure that you can see hidden folders. You can find your AppData folder very quickly by entering "%appdata%" in the address bar of the file explorer.
Shutdown your Nxt client (using the NXT icon in your Windows system tray), and place the nxt_db folder into your "C:\Users\USERNAME\AppData\Roaming\NXT" folder.
Start the Nxt client again and the download should be up-to-date quickly.
On MacOS (when using Nxt mainnet) your default user directory is ~/.nxt and ~/.ardor for Ardor
Also see User directories per product and platform