The official DuckDuckGo browser for Windows cannot be downloaded for Windows 8.1 and does not have an official portable version Key Compatibility and Availability Issues Operating System Requirement : The official DuckDuckGo browser requires Windows 10 (version 19041.0 or higher) or Windows 11
Change your browser search settings to route all address bar queries directly through DuckDuckGo.
DuckDuckGo does not release a .zip or portable executable ( .exe ) package for their desktop browser. The official distribution method is a standard Windows Installer ( .exe or MS Store).
Open the browser and set as your default search engine.
: There is no standard offline MSI or EXE installer for the browser; it typically uses a launcher that pulls the latest release from the web during installation Privacy Alternatives for Windows 8.1