You can manually add media to the media catalog, or you can import media from a printer or from an XML file. However, you can always restore the default media catalog. The existing media catalog will be replaced with the default media catalog. Any non-default media will no longer be available in the catalog. If non-default media is used in your document, the media is not deleted from your document.
Click [Tools] - [Media] - [Media catalog].
The [Media Catalog] dialog will appear.
Click [Restore].
Confirm that you want to replace the existing media catalog with the default media catalog.