A frequency domain method for bifurcation analysis of nonlinear dynamical systems is developed. The proposed method consists in directly tracking the bifurcation points when a system parameter is varied. The method is based on extended systems, Harmonic Balance Method and arc-length continuation. An original extended system for the detection and tracking of Neimark-Sacker (secondary Hopf) bifurcations is introduced. With only one computation a map showing the stability boundaries and changes of dynamical regime is obtained.