Hi Mark, I notice your profile lists ViewNX2 as your browser. In either ViewNX2 or CaptureNX2 white balance adjustment is the same except that CNX2 gives more powerful options.
When you have a raw NEF image opened and you click on WB adjustment the default is "As Taken" and this is not adjustable. From there you can chose the WB setting you require.
Normally it is just a small tweak required and I select "automatic" and then tweak using the sliders. If there is a white or grey object anywhere in the image "Set Grey Point" is the most efficient way by just clicking on the white object.
In CaptureNX2 you can also set Red and Blue points but I have seldom needed that - in fact if you nail the exposure the camera's Auto WB is generally very close :>)
Regards, Clive Liddell Pietermaritzburg South Africa