It is shown that the existence of majorons, which enable a heavy neutrino, 500 eV <~ mνH <~ 25 keV to decay into a light neutrino mνL <~ 8 eV and a majoron, with lifetime 104 yr <~ τνH <~ 108 yr can solve both the large and small scale dark matter problems. For a primordial ``Zeldovich'' spectrum of fluctuations the limits are mvH<~ˇ550eV and τvH > 107 to 108 yr (the ranges mνH <~ eV and τνH >~ 108 yr are allowed by the model but galaxy formation becomes problematic). The large scale dark matter problem is how to achieve the critical density as implied by inflation, the small scale problems deal with the halos of galaxies and galaxy formation and perturbation growth. The heavy neutrino could provide the solution to the small scale problem by initiating perturbation growth before decoupling. The decay products will be fast and thus not bound to the initial clumps, thus solving the large scale problem. The low mass relic neutrinos that were not decay products would remain bound in the gravitational potentials which grew from the initial perturbations. The resulting universe would be radiation dominated, which is consistent with present observations if H0 <~ 40 km/s/Mpc. An alternative solution can occur when mνH ~ 10 eV: the universe can again become matter dominated in the present epoch. This solution still allows H0 ~ 50 km/s/Mpc. The majoron model parameters which best fit the dark matter considerations are presented.