Traktor 2.5.1 ?
were do i download it from ?
Seriously…? Service Centre.
It’s good to run Service Center now and then, you get all kinds of other upgrades like latest S4 drivers and so on. Of course this excludes pirated software users that are on their own and just pray their pirated SW will work properly at a gig, or not.
Service Center or you can DL the demo from the website and plug in your serial number to get whatever flavor of Traktor you have.
http://www.native-instruments.com/#/en/products/dj/traktor/?page=2118