It looks like you’re trying to find EnfuseGUI 2, the free edition released in 2009.
Unfortunately, that version relied on Microsoft libraries that were retired in 2019 and are no longer available—so EnfuseGUI 2 can’t run as intended on new setups.

In 2020, I rebuilt the app from the ground up, adding new features many had requested (like raw file conversion and image alignment), and moved to a subscription model to sustain ongoing development and hosting costs. At that time, the free edition was retired.

EnfuseGUI 3 now includes:
• Align Images
• Raw Image Processing
• Batch Processing

You can try EnfuseGUI 3 one month for free. The trial is fully functional—just click one of the links below to download and follow the in-app instructions to activate your trial.

As a thank-you for being a long-time user of EnfuseGUI 2, I’d be happy to offer a coupon giving you 20% off an annual subscription. After your trial, simply send an email (click 'Contact Support' from within the app) and I’ll give you a coupon code. One license-key can activate up to two computers.

EnfuseGUI is used to avoid blown-out highlights in an interior by using one set of exposures for the room itself, and another set for the windows. EnfuseGUI can blend these images together and create a final image where everything is properly exposed. EnfuseGUI can also be used for other purposes, like night photography and focus stacking.