It looks like you’re searching for EnfuseGUI 2, the free edition released in 2008.
That version relied on Microsoft libraries that were retired by them in 2019, and it can no longer install properly on modern systems.

In 2020, I rebuilt the application from the ground up—adding many features users had requested, such as RAW file support and image alignment. I also transitioned to a subscription model to support ongoing development and hosting costs. At that point, the free edition was officially retired.

What’s New in EnfuseGUI 3?
• Align Images
• Raw Image Processing
• Batch Processing


You can try EnfuseGUI 3 free for one month. The trial is fully functional—just click a download link below and follow the in-app instructions to activate your trial.
As a thank-you to long-time users of EnfuseGUI 2, I’m happy to offer 20% off an annual subscription. Any time during your trial, simply click 'Contact Support' from within the app and request your personal coupon code. Each license can be used on up to two computers.

EnfuseGUI helps photographers create perfectly exposed images by blending multiple exposures. For example, you can use one set of exposures for a room’s interior and another for the bright windows—EnfuseGUI blends them into a final image where both are properly exposed. It’s also great for night photography, focus stacking, and other exposure-blending workflows.