A: No, it is not illegal. It violates no law, but it violates Adobe’s EULA regarding "use on unsupported operating systems" only in terms of technical support—they won't help you if it breaks.
Despite the official stance, users across Reddit, TenForums, and Adobe Community forums have reported partial success. Here is what actually happens when you try to run the Setup.exe from the Acrobat 9 CD on a fresh Windows 11 Pro machine. is adobe acrobat 9 compatible with windows 11
If you must use Acrobat 9 for specific legacy workflows, you can attempt to use Windows . This is not a guaranteed fix but may allow the program to launch. A: No, it is not illegal
But with Microsoft pushing regular feature updates for Windows 11 (22H2, 23H2, and 24H2), a critical question arises: Here is what actually happens when you try to run the Setup