Dean Wette , Dec 08, 2006; 08:28 p.m.
Did your D50 come with Picture Project? If so, install that and then select "Check for updates..." from the Help menu. that will download and install the latest for you. That's what I did when I got my D200 earlier this week. Now I have 1.6.4.
I don't even know whether it's worth using. I have PS CS2 and Picasa2, and I can't find anywhere in Picture Project to see a RGB Histogram of my pictures.