One of the really nice things about GoldMine Premium is the ability to preview files directly from your Links tab without opening them. You can see this by clicking on your "Links" tab and then opening the Preview pane by clicking on the far right-hand edge (that is, if the preview pane isn't already visible).
However, we don't exactly live in an ideal world, and sometimes you may want to prevent certain file types form being previewed.
You can change this by going to Tools | Configure | System Settings. Click on the "Preview" tab. You can disable previewed file types in the list by removing the checkbox next to the appropriate type.