  Events with high energy isolated electrons, muons or tau leptons and missing
transverse momentum are studied using the full e^\pm p data sample collected by
the H1 experiment at HERA, corresponding to an integrated luminosity of 474
pb^{-1}. Within the Standard Model, events with isolated leptons and missing
transverse momentum mainly originate from the production of single W bosons.
The total single W boson production cross section is measured as 1.14 \pm 0.25
(stat.) \pm 0.14 (sys.) pb, in agreement with the Standard Model expectation.
  The data are also used to establish limits on the WW\gamma gauge couplings
and for a measurement of the W boson polarisation.
