Convert NRW to ARW

nrw to arw conversion seems to be related to attempts to make an export between two vendor specific digital RAW formats, namely from Nikon (.nrw) and Sony (.arw). This is perhaps doable, but RAWs are typically exported to some generic exchange format (like DGN) or exported to JPEG format. But in any case, your best option is to use some dedicated digital photo editor like Photoshop Lightroom.