  Axisymmetric magnetohydrodynamic (MHD) simulations have been applied to
investigate the interrelation of a central stellar magnetosphere and stellar
wind with a surrounding magnetized disk outflow and how the overall formation
of a large scale jet is affected. The initial magnetic field distribution
applied is a superposition of two components - a stellar dipole and a
surrounding disk magnetic field, in both either parallel or anti-parallel
alignment. Correspondingly, the mass outflow is launched as stellar wind plus a
disk wind. Our simulations evolve from an initial state in hydrostatic
equilibrium and an initially force-free magnetic field configuration. Due to
initial differential rotation and induction of a strong toroidal magnetic field
the stellar dipolar field inflates and is disrupted on large scale. Stellar and
disk wind may evolve in a pair of collimated outflows. The existence of a
reasonably strong disk wind component is essential for collimation. A disk jet
as known from previous numerical studies will become de-collimated by the
stellar wind. In some simulations we observe the generation of strong flares
triggering a sudden change in the outflow mass loss rate by a factor of two and
also a re-distribution in the radial profile of momentum flux and jet velocity
across the jet. We discuss the hypothesis that these flares may trigger
internal shocks in the asymptotic jets which are observed as knots.
