This is just a heads up, but Nvidia has removed the nvcuenc.dll file in the 340.52 video drivers recently released. This is the library and interface needed for CUDA hardware acceleration in many programs, like Mediacoder, Freemake and Mediaexpresso.
Nvidia still supports CUDA through their newer dll, the nvenc interface, but as of now, there are no free encoders that make use of the newer library. According to a post over at Videohelp.com, the developers of the various encoders using CUDA were taken by surprise by this move from Nvidia.
If you use one of the free CUDA encoders, the 314.07 drivers will work for you.