There should be options to view and edit your NEF files on your present computer. Some may just involve an extra step or two.

They will need to be converted to a tiff, jpg or dng file to bring into photoshop. If you can load your camera's software (View NX2?) onto your computer, then it will probably be able to convert the NEF files into a photoshop friendly format.

Faststone (free!) should be able to view NEF files, so at least you can look at the files. It is very light on computer resources, and is very good at batch renaming, resizing etc. It can also convert raw files, but when I last tried converting Canon CR2 raw files via Faststone, I wasn't impressed.

Adobe also provides a free converter for changing many different camera file types into the DNG format, which can then be used in Photoshop/Lightroom. It is the Adobe DNG Converter. I know it didn't support NEF files for a while, but hopefully it does now.