Create a separate Snow Leopard user account strictly for Adobe apps. This isolates permission changes and prevents conflicts with modern macOS data structure (if dual-booting).
(e.g., using a Creative Suite serial for a standalone Illustrator download). Time Machine Conflicts : On Snow Leopard, active Time Machine Adobe Illustrator Asking For Serial Number Mac Os X 10.6
Caution: This prevents Illustrator from updating license info, but it also stops deactivation. Only do this if you never plan to reinstall. Create a separate Snow Leopard user account strictly
: If you are installing an "Upgrade" version, the installer will ask for the serial number of a qualifying previous product Time Machine Conflicts : On Snow Leopard, active
Ironically, for some Snow Leopard users, Illustrator will still function after dismissing the serial number dialog repeatedly. Try closing the prompt 3–4 times. Some versions fall back to a 30-day trial mode indefinitely.