Installer and debug symbols available from https://npcap.org/#download . Npcap 0.997 was never publicly released; these are the changes since Npcap 0.996:
When upgrading Npcap, do not uninstall the existing Npcap until the user
clicks the Install button. Previously, the existing Npcap was uninstalled
prior to the first options screen, so that canceling the upgrade left no
working Npcap on the system.
Redefine the I/O control codes used by Npcap using the
ensure proper access control and consistent parameter passing. This is not a
published API, but the change will require that Packet.DLL and the npcap
driver are the same version.
Fix a 1-byte overrun in NPFInstall.exe when killing processes with Npcap DLLs
In cases where PacketOpenAdapter is given an adapter name in UTF-16LE,
translate it to ASCII before doing string operations on it. See
Significant reorganization of internal data structures to reduce memory use
and initialization overhead.