It might be old drivers in the registry screwing something up. I would uninstall the current NV drivers, then run Display Driver Uninstaller (it replaced Driver Sweeper, just do Google search for the download file). Definitely let it reboot you into Safe mode. Then it will find all kinds of old versions and files...let it delete them all and reboot into normal mode.
Then run CCleaner (search and download that) to delete anymore crud out of the registry.
Reboot and then install the latest NV drivers, and hopefully BOINC will pick it up.