If you already own a valid CS3 license, Adobe previously provided a way to continue using it without needing a generator: [Locked] Authorization Code for CS3? - Adobe Community
If you have a legal CS3 license key but lost the installer, try: If you already own a valid CS3 license,
Adobe Photoshop CS3, released in 2007, is remembered fondly by many designers and photographers. Its relatively lightweight performance compared to modern Creative Cloud versions makes it attractive for older computers or users who prefer classic workflows. try: Adobe Photoshop CS3