  We employ an improved methodology to insert live stellar disks into
high-resolution dark matter simulations of Milky Way sized halos, allowing us
to investigate the fate of thin stellar disks in the tumultuous environment of
cold dark matter structures. We study a set of eight different halos, drawn
from the Aquarius simulation project, in which stellar disks are adiabatically
grown with a prescribed structure, and then allowed to self-consistently
evolve. The initial velocity distribution is set-up in very good equilibrium
with the help of the GALIC code. We find that the residual triaxiality of the
halos leads to significant disk tumbling, qualitatively confirming earlier
work. We show that the disk turning motion is unaffected by structural
properties of the galaxies such as the presence or absence of a bulge or bar.
In typical Milky Way sized dark matter halos, we expect an average turning of
the disks by about 40 degrees between z=1 and z=0, over the coarse of 6 Gyr. We
also investigate the impact of the disks on substructures, and conversely, the
disk heating rate caused by the dark matter halo substructures. The presence of
disks reduces the central subhalo abundance by a about a factor of two, due to
an increased evaporation rate by gravitational shocks from disk passages. We
find that substructures are important for heating the outer parts of stellar
disks but do not appear to significantly affect their inner parts.
