A Kontakt instrument might often include different file types while others might not. Essentially all you need for a plain basic Kontakt instrument is the samples and the .nki (instrument file). So what are all the other file types?
.NDX – Kontakt Index File
.ndx are generated when analyzing samples to create AET layers. (Authentic Expression Technology). AET basically allows you to capture spesific spectral characteristics of one sample and apply it to another.
.NICNT – Kontakt Activation File
Stores Activation & info for the sample library. When you add a library to Kontakt in the “rack list” Kontakt will check with the Service Center to see if the library can be registered.
.NKI – Kontakt Instrument File
An .nki holds one Instrument, it contains samples info of an instrument or other sounds that were pre-recorded for use in the sampler.
.NKM – Kontakt Multi File
An .NKM holds & Saves multiple instruments and their presets, which allows the instruments to be saved together.
.NKB – Kontakt Instrument Bank
A bank file is just a container for multiple instruments (Best with keyswitches instruments), which allows multiple instruments/samples to be assign MIDI channels and program changes.
.NKP – Kontakt Preset File
Kontakt Presets File, Contains, Effects, Filters, Modulators and such for use on Samples in Kontakt.
.NKR – Kontakt Rresource File
Resource Container file, it holds graphics, scripts, and IR samples.
.NCW – Kontakt Lossless Compression Audio File
Saves an imported wave audio file using compression methods so the file uses less disk space. NCW files are stored using lossless compression, so there is no loss in sound quality. Additionally, the files can be converted back to the original .WAV files without loss in quality.
.NKX – Kontakt Protected Monolith
Kontakt Player files: These Kontakt monolith container files consist of the digital audio sample data combined with associated patch details, and these pieces of data can also be separately stored in multiple files to allow users with easier options for using their audio samples with other audio sample editing and development applicat
.NKC – Kontakt Cache File
The .nkc file contains information about .NKX/.NKI audio samples for KONTAKT samples library. (Has a list on which position each file within a monolith starts).
So now you know what all these file formats are on your computer. If you have any questions just leave them in the comments and I will try to answer them.