Using CS4 - in the past PS set up a file for images saved for "web

I am using PS and Dreamweaver CS4. In the past, when saving an image for "web and devices", PS set up a separate file for saved images which then showed up in Dreamweaver. I have somehow lost PS in Dreamweaver. Instead, Photoshop puts the saved image back into the original file.PS is grayed out in Dreamweaver so cannot connect back to any images from Dreamweaver either. How do I get back to preferences I originally set up for saving images for web and devices. I have Windows XP Professional.