Simulations of Coronal Mass Ejections (CMEs) evolving in the interplanetary (IP) space from the Sun up to 1 AU are performed in the framework of ideal magnetohydrodynamics (MHD). The aim is to quantify the effect of the background solar wind and of the CME initiation parameters on the evolution and on the geo-effectiveness of CMEs. The shocks and magnetic clouds related to fast CMEs in the solar corona and interplanetary space play a crucial role in the study of space weather. Better predictions of space weather events require a deeper insight in the physics behind them. Different solar wind models are considered in combination with different CME initiation models: magnetic foot point shearing and magnetic flux emergence. The simulations show that the initial magnetic polarity substantially affects the IP evolution of the CMEs influencing the propagation velocity, the shape, the trajectory (and, thus, the geo-effectiveness).