I am using Solidworks 2015 and running windows 7.
"Show thumbnail graphics in Windows Explorer" is checked
"Always show icons, never thumbnails" is unchecked
"Display file icon on thumbnails" is unchecked
I still can't get any file previews to show in the preview pane.
Have you check your system options? it is a performance setting option to uncheck "do not show preview" on open file or something like that...
Mark