If you open a photo in Windows Photo Viewer and press the right arrow, it will move to the next photo in the folder. However, it will skip any non-photo file types (e.g. txt, doc, xls). It will include image types (jpg, png, tif, etc.)
Where can I control which types are included? The aim is to
include exclude raw files from my camera (.orf) which are currently being included. (Note that orf files are not currently associated to be opened by Photo Viewer)
EDIT: the reason for doing this is that I take pictures with my camera in Raw+JPEG mode and both end up in the same folder, but when browsing with Windows Photo Viewer I don't want to see every photo twice.