You're probably referring to Nikon Transfer 1.5.x and you've recently installed View NX2, which installs a Nikon Transfer 2.1.x version unseen to the user. When that happens, some options get reset by the Transfer 2.1.x installation. You need to open View NX2, click the Transfer button, change your options there, then close Transfer 2. After that, Transfer 1.5.x should work correctly. Why Nikon decided they needed two versions of Transfer I have no idea, as they are functionally identical for the most part. They don't install into the same folder on your computer, which creates additional issues. Simply put, this is insane software practice on the part of Nikon, and guaranteed to produce support issues like this one.
Current recommendation: if you've installed View NX2, remove Nikon Transfer 1.x from your computer and use Transfer from within the latest version of View NX-i. Some cameras are not supported by the old version. But a better recommendation: stop using Nikon's software.
