Delete preview files
When you play a movie, Adobe Premiere Elements combines the tracks and effects in the background, while playing the resultant movie in the Monitor panel. If you instead render the movie, Adobe Premiere Elements creates preview files and saves them on your hard disk. Once rendered, Adobe Premiere Elements needn’t process the tracks and effects again and can play the preview files directly. Similarly, preview files can save time when you export the final movie because Adobe Premiere Elements can use the information stored in the preview files rather than render again.
With the Timeline or Sceneline active, choose
Timeline > Delete Render Files. When prompted, click OK.
Note: It is important to delete preview files using the Delete
Render Files command rather than deleting them directly in Windows.
Projects refer to preview files in much the same way they do source
media. If you move or delete preview files without using the command,
the next time you open the project, Adobe Premiere Elements prompts you
to locate the files.