Notes about the NPZ file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The NPZ file type is primarily associated with 'nProtect' by INCA Internet Co, Ltd.. nProtect is a new Web-based anti-hacking & anti-virus tool designed to protect PC terminals from being infected by viruses or hacking tools. A game client which uses GameGuard downloads .NPZ files and extracts them for game hacking protection. NPZ files are mostly GameGuard updates located at the game server's host. When downloading a game client with GameGuard, first the GameGuard initializes itself, checks for updates, and if any, downloads NPZ files from the remote host (probably the game server's host).