  We present a complete calculation of the electroweak one-loop corrections to
the relic density within the MSSM framework. In the context of the neutralino
as dark matter candidate, we review different scenarios of annihilation and
coannihilation with a chargino. In particular we investigate predictions for
the annihilation into gauge boson pairs for different kinds of neutralino:
bino-, wino- and higgsino-like. We present some interesting effects which are
not present at tree-level and show up at one-loop. To deal with the large
number of diagrams occuring in the calculations, we have developed an automatic
tool for the computation at one-loop of any process in the MSSM. We have
implemented a complete on-shell gauge invariant renormalization scheme, with
the possibility of switching to other schemes. We emphasize the variations due
to the choice of the renormalization scheme, in particular the one-loop
definition of the parameter tan(beta).
