nwhak.exe is a user content creation tool to create packages of nwn files. Think of them as a zip of various types of files (textures, sounds, text, materials, ...). That package can then be used on modules, for instance.

Beamdog says that this tool is available on the install directory of the game, but apparently the GOG version doesn't have it. At least it's not on my install.

Does anyone have this issue?

Thanks in advance.

Dunno about the GoG version but Steam and Beamdog versions have it living in the gamedirectory:
.\bin\win32\nwhak.exe

I don't think the tool nor the data format have been updated so you could use the one from the diamond edition if you have access to that. Version of the tool distributed by Steam/Beamdog is: 1.0.4.0

Aw, crap! You are right! nwhak.exe is in .\bin\win32\nwhak.exe
I don't know how i missed this directory. I guess i was mislead by this:
https://nwn.wiki/display/NWN1/HAK#HAK-nwhak.exe
I wrongly thought it was in the main directory, but in fact nwmain.exe is in .\bin\win32. My bad.

Thank you for your help passionata!

You are welcome, glad I could help. I always wondered why it is not living in .\utils where GFFEditor.exe lives ;)