If you are a student, email Zerene Systems — they offer a of the latest Pro version. If you are a hobbyist, use the free Personal Edition (limits output to 1024x768, but perfectly legal).
The system requirements for running Zerene Stacker 1.04 Pro Portable.zip are: Zerene Stacker 1.04 Pro Portable.zip
Users should be aware that "portable" versions found online (especially .zip files from non-official sources) may violate official software licensing agreements. Always ensure you are using a legitimate license [1, 3]. Learning Curve: If you are a student, email Zerene Systems