Evolution of the (a) mass averaged magnetic field B in the disc (of 4 kpc height and 10 kpc radius); (b) mass averaged ratio of B_z over B in the disc (c) mass averaged B_z in the wind (more than 2 kpc away from the disc) (d) mass averaged ratio of B_z over B in the disc wind; mass average norm of B in the wind. The mean magnetic field strength in the disc saturates at ⟨B⟩≃5 μG with a similar vertical structure in all of the simulated cases. In the wind, a clear difference appears when adding diffusion (isotropic or anisotropic), and the vertical component is more than ten times greater with CR injection and diffusion than without CR injection.