if thumbnails are not appearing, you can re-install it through the Windows Control Panel:
Some users find that uninstalling the Shell Extension specifically (via Add/Remove Programs) and then re-adding it through the "Modify" menu resolves persistent cache issues. Version Compatibility: corel graphics windows shell extension download
The is a utility that allows Windows Explorer to display high-quality thumbnails for CorelDRAW ( .cdr ), Corel DESIGNER ( .des ), and other Corel-specific file formats. If you are seeing generic icons instead of visual previews for your design files, you likely need to install or repair this extension. How to Get the Shell Extension if thumbnails are not appearing, you can re-install