Chrome Downloading with Google Chrome — 3 steps
Chrome usually downloads the file right away. The first time you run it, follow steps ①②③ below. (The screenshots show the Korean Windows UI — the buttons appear in the same position in every language.)
1In the "Windows protected your PC" window, click "More info".

2Click the "Run anyway" button that appears.

3Click "Yes" in the User Account Control prompt.

Edge Downloading with Microsoft Edge — 4 steps
Follow ①②③ when saving the file, then ④ the first time you run it. (Screenshots show the Korean Windows UI — same buttons, same places.)
1In the download notice, click ⋯ (More actions) next to the file.

2Click "Keep" in the menu.

3In the confirmation window, click ▾ next to [Delete], then click "Keep anyway".

4When you run the file, click "Yes" in the User Account Control prompt.

✅ Why does this notice appear? HanFlow PDF is an official program made by Quantum Materials Inc. and contains no viruses. Windows simply marks newly released software as "unknown publisher" for a while. It is safe to install following the steps above.
💡 After installation, launch HanFlow PDF from the desktop or the Start menu.