Check that you media cache files are not located on the C: drive in Preferences. Move them to another drive. Then delete the Media Cache directory from your C: drive and defrag.
Thanks for the reply. The Media cache files aren't on the C drive.... and the source files are also on another drive. Not sure what is going on. Can you tell me
where the Media cache files are on the C drive, if so I can check and see what is there. Also, do you know where the render files are normally located? I'm
thinking that the rendered files are on the C drive. Thanks for your help.
Default location for Media Cache Database files on a PC:
C:\Users\Your Username\AppData\Roaming\Adobe\Common\Media Cache and
C:\Users\Your Username\AppData\Roaming\Adobe\Common\Media Cache Files
Go to Edit -> Preferences -> Media... to check it.
Rendered preview files are normally stored in the same folder where you save your .prproj file(s), in Adobe Premiere Pro Preview Files subfolder.