In the event you want to utilize your previous search criteria so you can redo or revise your last search click "File" to open the file menu on the Search Criteria window (not the main INTERFACE™ file menu) and then click "Last Search".
If you do not see "Last Search" on the file menu then you have opened the wrong file menu. You probably opened the main INTERFACE™ file menu by mistake rather than the file menu on the Search Criteria window as described above.
See also the page on Blanking your Search using INTERFACE™.