  We solve the time-dependent dynamics of axisymmetric, general relativistic
MHD winds from rotating neutron stars. The mass loss rate is obtained self
consistently as a solution of the MHD equations, subject to a finite thermal
pressure at the stellar surface. Conditions are chosen to be representative of
the neutrino driven phase in newly born magnetars, which have been considered
as a possible engine for GRBs. We compute the angular momentum and energy
losses as a function of $\sigma$ and compare them with the analytic expectation
from the classical theory of pulsar winds. We observe the convergence to the
force-free limit in the energy loss and we study the evolution of the closed
zone for increasing magnetization. Results also show that the dipolar magnetic
field and the presence of a closed zone do not modify significantly the
acceleration and collimation properties of the wind.
