NI Kontakt Player 2 is included in this product!
Free hard drive space - depending on the regarding library content.
You can use this library with the free Kontakt Player 4 (or higher) which is compatible to all actual operating systems and interfaces on Mac & PC
Note on Support for KONTAKT Player products:
Native Instruments only provides Registration/Activation support for KONTAKT Player products. Technical support is managed by the manufacturer of the respective products/libraries.
An internet connection on any computer is required to authorize / activate the product (Challenge/Response).
Q: Can I use the included Kontakt Player for playing other libraries in Kontakt format (.nki plus .wav files)?
A: No, they only work in a 15 minutes demo mode
Q: When trying to "Add Library" my Kontakt shows a message "No Library found"
A: Then this is not a protected Kontakt library, but an open Kontakt format. You can find additional hints for Kontakt Libraries in that Sounds & Gear Video