The RAW plugin was installed with Photoshop CS for me. It was under plug-ins/ file formats. The 2.4 replacement is available from Adobe, and replaces the existing file. RAW is non processed data from the sensor. A jpg is the sensor data with post processing. The RAW data comes from the camera. Some applications can read RAW data. Each camera produces its own flavor. The 2.4 plugin supports more cameras. Raw Shooter supports several cameras, also. I have a Canon camera, and it has comes with Canon software. If you had a RAW file, PSCS might see it if the plugin supports that flavor. Rich