QTR-Quadtone RIP

Hi out there,
This my first time using this sit. I am having a problem with QTRgui. 
When I open it the first time after starting my computer it works but 
if I close QTR and then reopen it will not recognize the printers or 
print. Has anyone else had this problem? I am not very good with 
computers. When I was young and my brain worked they didn't exist.
Thank you Dennis