  A search for TeV - PeV muon neutrinos from unresolved sources was performed
on AMANDA-II data collected between 2000 and 2003 with an equivalent livetime
of 807 days. This diffuse analysis sought to find an extraterrestrial neutrino
flux from sources with non-thermal components. The signal is expected to have a
harder spectrum than the atmospheric muon and neutrino backgrounds. Since no
excess of events was seen in the data over the expected background, an upper
limit of E^{2}\Phi_{90% C.L.} < 7.4 x 10^{-8} GeV cm^{-2} s^{-1} sr^{-1} is
placed on the diffuse flux of muon neutrinos with a \Phi \propto E^{-2}
spectrum in the energy range 16 TeV to 2.5 PeV. This is currently the most
sensitive \Phi \propto E^{-2} diffuse astrophysical neutrino limit. We also set
upper limits for astrophysical and prompt neutrino models, all of which have
spectra different than \Phi \propto E^{-2}.
