XYplorer does not preview RAW and PSD images. What can I do about that?
You need to install the necessary codecs. There are many possibilities, free or paid. Here is a paid one:
FastPictureViewer Codec Pack
Costs $9.99 (as of 17-Oct-2017) and works for all RAW formats supported by XYplorer, including PSD. It will provide preview, thumbnails, and metadata.