Hi I would like to help .
Many of Nikon's digital cameras can shoot images in raw format which contains everything its sensor sees. The NEF format can also contain a JPG and TIFF version of the same image.
File Juicer can extract the JPEG and TIFF version in the simplest possible way without conversion.
This simple application can get to the files you need , inside the NEF .
Here is another option do do this job . http://www.contenta-nefconverter.com/
And one more : - http://www.nikonusa.com/Nikon-Products/Product/Imaging-Software/25385/Capture-NX-2.html#tab-ProductDetail.ProductTabs.CompatibleWith
Do you have any questions ? Thanks.