Navigator 3.x:

-Go to the Options Menu
-Go to Network Preferences
-Click on the tab named Cache
-Click on "Clear Disk Cache Now"

Communicator:

    -Go to Edit | Preferences| Advanced | Cache

    -Click on "Clear Disk Cache Now"

** Note: If these do not succeed, try deleting the entire cache folder/directory along with the netscape.hst file.   They will be rebuilt upon starting up Netscape again.  Netscape.hst is the history file and also keeps visited links colored.

Internet Explorer 3.0:

   - View
   - Options
   - Advanced
   - Temporary Internet Files: Settings
   - Empty Folder