Stephen, Nikon View NX is also free and includes both conversion from NEF and basic corrections and quite a good pre-viewer.

Capture NX is also available for 30 day free trial (make sure you use the Nikon EU site, see NX thread in digital darkroom).

I know it is not a popular view, but I find Capture NX is brilliant (for a naturalistic approach) and have not opened PSE since I got it last December. Turn your starying into RAW into a positive advantage!