only saves as PTO

[Lord Baccus]

how do I change it to Tiff or Jpg?

[dkloi]

If you're using the Simple interface, you need to press the button "3. Create panorama..." which will stitch the images and create a tiff. In the Advanced or Expert interface, you need to go to the Stitcher tab and press "Stitch!" in order to create the panorama that you can save in tiff format. The PTO file is the project file that stores the alignment, exposure settings, and other parameters about how you create the panorama.