To activate ArcSoft PhotoStudio 6 legally, you must use the unique license key provided at the time of purchase. Because ArcSoft has discontinued the software and its official web store, obtaining new activation codes directly from the developer is no longer possible. How to Find Your Activation Code
Since the product is end-of-life (EOL), there are no official servers to validate new registrations, meaning even a "real" key found online may fail to activate. How to Get a Legal Activation Code arcsoft photostudio 6 activation code serial number
I've lost my activation code or serial number - Clip Studio Support To activate ArcSoft PhotoStudio 6 legally, you must
: No support for third-party Photoshop plug-ins; internal zoom tools can be coarse; official customer support is now effectively non-existent. Activation & Serial Numbers Launch PhotoStudio 6 on your computer