You'll need to activate your copy using a serial number. This process usually involves creating an account on the Native Instruments website, then entering the serial number from your purchase.
Native Instruments Traktor Pro 3 was officially succeeded by Traktor Pro 4
: Using software without a valid license is illegal under modern copyright laws and can lead to hefty fines, lawsuits, or even criminal charges in some regions. Authentic Features of Traktor Pro 3/4