Photoshop CS3 Extended includes all of the same features as Photoshop CS3 but adds a brand-new set of tools and capabilities for the integration of 3-D models, video and animation, and image measurement and analysis.
In CS3, Adobe did a very good job of making interface improvements without moving too far away from the familiar. Most of the new elements unique to Photoshop Extended are well integrated into the standard Photoshop and accessed from familiar tools such as the Layers panel or various menus. 3-D compositing and texture editing.
-Open the downloaded file with WinRAR.
-Extract the "Adobe Photoshop CS3 Extended Portable"
-Run the "photoshop.exe"