  Using the StarTrack population synthesis code we analyze the possible
formation channels of the Galactic microquasar GRS 1915+105 harboring the most
massive known stellar black hole. We find that we are able to reproduce the
evolution and the current state of GRS 1915+105 in a model with lowered wind
mass loss rates in massive stars. We conclude that the existence of GRS
1915+105 implies that stellar winds in massive stars are a factor of two
weaker, but still within observational bounds, than used in stellar models. We
discuss the mass transfer initiated by the massive primary in binaries which
are the possible precursors of systems harboring massive black holes. We show
that such mass transfer evolution is neither clear case B nor C, but instead is
initiated during the core helium burning phase of the massive donor star, the
progenitor of the black hole. We also argue that massive black holes do not
receive any kicks at their formation and are formed through direct collapse of
progenitor star without accompanying supernova explosion.
