Nikon has released NEF Codec Version 1.18.1, which adds support for D600 .NEF files on Windows PCs. You can download the new codec here on Nikon’s website.
Microsoft has released a new camera codec pack that will allow RAW files for supported cameras to be viewable in Windows Explorer and other software that’s based on Windows Imaging Codecs.
Loads of new and old cameras are supported, including the latest models like the Canon 5D mark III and Nikon D800. More details on Microsoft’s website.