Since NI service center is replaced by Native Access service , the only solution to run the old versions of Traktor Scratch Duo and Pro software on Windows 10 is to download the Traktor Pro installation file and the latest audio 4 / audio 8 drivers available from here :
https://support.native-instruments.com/hc/en-us/articles/360000618297-Compatibility-of-Native-Instruments-Products-on-Windows
https://www.native-instruments.com/en/support/downloads/drivers-other-files/
Enjoy
