: Sign in to your Adobe Account and navigate to "Registered Products" under the "Plans and Products" section. Your 24-digit serial numbers for all registered legacy software will be listed there.
If you have a legally purchased copy of Illustrator CS5, you can find your serial number using the following Adobe Help resources: Adobe Illustrator Serial Number Cs5 List
: Search your inbox for "Adobe," "serial number," or "order confirmation." Online retailers like : Sign in to your Adobe Account and
If you've lost or forgotten your Adobe Illustrator CS5 serial number, don't worry. Here are some steps you can take: " "serial number