Most of the images acquired in the NIC will have an image format that is not readable by the basic image viewers built in to Windows and Mac computers (e.g. Windows Media Viewer or Preview). Here are a couple free solutions:
Fiji
Fiji is a freely available distribution of ImageJ that comes comes pre bundled with a number of useful plugins, including Bio-Formats which can read that vast majority of proprietary image formats used in microscopy, such as the .nd2 files acquired when using Nikon Elements. Fiji is also capable of handling 12 and 16-bit TIF files such as those acquired in Metamorph.
NIS Elements Viewer
NIS-Elements Viewer is a free standalone program to view image files and datasets with the Nikon .nd2 file format. It offers the same view and image selection modes as the NIS-Elements core packages and has the same look and feel as the NIS-Elements core packages, but lacks the advanced analysis features of Nikon Elements. Saving ND datasets to TIFF files is also possible with the NIS-Elements Viewer.