  The annihilation of neutralino dark matter may result in observable signals
in different wavelength. In the present paper we will discuss the effect of
neutralino annihilation in the halo of our Galaxy and in its center. According
to high resolution cold dark matter simulations, large virialized halos are
formed through the constant merging of smaller halos appeared at previous
times. At each epoch, dark matter halos have then a clumpy component which is
made of these merging subhalos. The annihilation of dark matter in these
clumps, always present in the halo of our Galaxy, may be responsible for
appreciable fluxes of $\gamma$-rays, potentially detectable. We find that,
depending on the fundamental parameters of the clump density profile and on the
distribution of clumps in the Galactic halo, the contribution to the diffuse
$\gamma$-ray background from clumps could be used to obtain constraints on the
neutralino properties such as mass and annihilation cross section. On the other
hand the annihilation of neutralino dark matter in the galactic center may
result in radio signals. At the galactic center, infact, the accretion flow
onto the central black hole sustains strong magnetic fields that can induce
synchrotron emission, in the radio wavelength, by electrons and positrons
generated in neutralino annihilations during advection onto the black hole. We
find that the observed emission from the galactic center is consistent with
neutralinos following a Navarro Frenk and White density profile at the galactic
center while it is inconsistent with the presence of a spike density profile,
supposed to be generated by the formation history of the central black hole.
