You DON'T want to use Nikon Transfer! It corrupts the files so that Lightroom cannot read them. But here is a link to a utility that will repair the files. I have never used it, only seen it recommended.
Fix Corrupted Nikon NEF Images
In the future, I strongly suggest that you simply use Lightroom to import your images. It works well. There is no need whatsoever to use Nikon Transfer. There is every reason not to use it.