Photoshop CS3 supports many new image dimensions as well as files and as such it requires more advanced system performance when compared to its predecessor. The maximum file size that it can support is 300,000 x 300,000 pixels, except for PDF files because those are still constrained by the 30,000 x 30,000 pixel limitations. Adobe Photoshop CS3 3 GETTING STARTED OPENING Begin by opening Adobe Photoshop CS3. On a PC, click Start Programs Adobe Photoshop CS3, or click on the shortcut on the desktop. On a Mac, click Macintosh HD Applications Adobe Photoshop CS3 Photoshop CS3. Oct 27, 2019 Adobe Photoshop CS3 Windows 7 support is coming to an end, so I bought a Dell with Windows 10 and downloaded my Adobe photoshop CS3 installation disc and it downloaded but it will not open. The message is 'Adobe photoshop CS3 is not responding'. Begin by opening Adobe Photoshop CS3. On a PC, click Start Programs Adobe Photoshop CS3, or click on the shortcut on the desktop. On a Mac, click Macintosh HD Applications Adobe Photoshop CS3 Photoshop CS3 shown in Figure 1, or click the icon in the Dock. Navigation to Photoshop CS3 on a Mac SETTING UP THE DOCUMENT.