The generation and growth of surface water waves by the wind and including modified boundary conditions appropriate for the presence of surfactants at the surface are reconsidered using linear instability theory to describe the process. The new features of our work are the inclusion of both surfactants and a wind drift layer. We allow a coupled mean flow in both the air and water; the depth-dependent mean flow is considered to be wind-induced. The complex wave frequencies are determined numerically. Uncontrolled numerical errors associated with a direct numerical solution of the Orr-Sommerfeld equation for the coupled mean flow are avoided by solving an associated equation obtained by a Riccati transformation of the original equation, allowing a straightforward and efficient determination of the eigenvalues of the linear stability problem. A different aspect of our analysis is the change of surface boundary conditions due to contamination of the surface, notably, the change of tangential stress at the surface due to surface tension gradients induced by the film (known as the Marangoni effect). Comparisons are made with previous work on both film-free and contaminated surfaces. The dominant effect of introducing film boundary conditions is a large change in the wave number of the most unstable wave with an attendant reduction in the growth rate. Implications for wind wave growth on the ocean are discussed. ¿ American Geophysical Union 1992