I also have a home network drive, and in fairness, I've never gotten those RAW files to display as thumbnails. ARW (Sony) thumbnail files but inside my computer only the icon shows perplexes me. I have gone into a variety of menus and have made sure the 'display as icons instead of pictures' box is unchecked trying to get my new computer to display properly, but no luck so far.

in fact when the folder opens icons are displayed and I can see sequentially the system converting them to thumbnail pics right before my eyes. Also, my external drive where I have RAW pictures saved shows them as thumbnails, but with my new Windows 8 system my 2 internal drives just show icons, but the USB external drive continues to convert the RAW files to thumbnails. On the old Windows 8 system my RAW picture files displayed as thumbnails.

I recently exchanged a new Windows 8 computer that did not meet my needs for a newer one that does meet my needs (hardware-wise).