  Collective properties of a quasi-two-dimensional (2D) system of spatially
indirect magnetoexcitons in coupled quantum wells (CQW) in high magnetic field
$H$ were analyzed in the presence of disorder. The Hamiltonian of the dilute
gas of magnetoexcitons with dipole-dipole repulsion in a random field has been
reduced to the Hamiltonian of a dilute gas of dipolar excitons without an
applied magnetic field, but in an $H$-dependent effective random field and
having an effective mass of magnetoexciton which is a function of the magnetic
field and parameters of the CQW. For 2D magnetoexcitonic systems, the increase
of the magnetic field $H$ and the interwell distance $D$ is found to increase
the effective renormalized random field parameter $Q$ and suppress the
superfluid density $n_s$ and the temperature of the Kosterlitz-Thouless
transition $T_c$. It is shown that in the presence of the disorder there is a
quantum transition to the superfluid state at zero temperature T=0 with respect
to the magnetic field $H$ and the parameters of the disorder. There is no
superfluidity at any exciton density in the presence of the disorder at
sufficiently large magnetic field $H$ or sufficiently large disorder.
