Your problem is that RawShooter won't recognize Raw files from newer cameras...and it doesn't have an update because they were bought out by Adobe, some time ago.
As mentioned, each new camera's RAW files are slightly different, and the software must be updated for the new camera's files. Photoshop puts out updates every few months, to support the new cameras that have come out.
RawShooter is a great program, provided that you have an older camera (from before it was bought out). Somewhat similar (and probably a lot better) than RawShooter is Adobe Lightroom, you might consider that.
If you don't want to buy new software, then just use the program that came with your camera.
'RAW' is a generic term...but the actual file types/extensions are different for different cameras/companies. All Nikon RAW files are .NEF while Canon's Raw files are .CR2