Drivers are becoming the larger part of operating systems kernels. Previous studies have shown that device drivers seem to be one of the most important sources of operating systems misbehavior. Their failure can have significant impact on the kernel and cause significant damages to the system as a whole. To objectively characterize the impact of faulty drivers, we have carried out a series of fault injection experiments. To conduct these experiments we have targeted the DPI (Driver Programming Interface) that implements the way device drivers interact with the kernel. Faults are injected on the parameters of these kernel core functions. This allows for the derivation of useful results about the failure modes induced and thus characterization of the robustness of a target kernel with respect to faulty drivers. The information gathered also enables to improve these interaction facilities.