We are working together with Nvidia on an updated CUDA version of the OpenMM core to solve the issues with Nvidia drivers and to create a sustainable solution that will bring speed improvements.
In the meantime, we strongly encourage you to try the hotfix( http://nvidia.custhelp.com/app/answers/detail/a_id/4288 ) or downgrade to the last known working Windows NVIDIA driver (372.70) if you would like to continue folding core 21 (OpenMM) GPU projects.
Thank you for your patience and support.
Sincerely the Folding@Home core 21 team.