This thread has the answer to why a pop-up window suddently began to appear when I booted up my Windows XP box at home. I had installed Apache and a demo of the Zend PHP editor. The pop-up error began once the demo license expired yet it gave no indication of what system was causing the error. I thought I had gotten infested with a virus until a little googling turned up that thread above. Zend needs to improve that error to something meaningful.