Select the Help - Switch to Demo Mode menu option to use all of CopyCAD functionality in demonstration mode only.
This option is only available when you have not purchased a licence for one of the CopyCAD modules. If you switch into demo mode you can demonstrate and evaluate unlicensed functionality. You will not however be able to save any models.
To return to your normal CopyCAD mode, you must close CopyCAD and reopen it.