There is currently no official portable version DuckDuckGo , and the standard version is not compatible with Windows 8.1 . The browser officially requires Windows 10 (May 2020 update) or later DuckDuckGo Key Compatibility & Availability Limitations Operating System Requirement:
Windows 8.1 is insecure by modern standards. Microsoft stopped providing security updates in early 2023. If you browse the open web on a standard browser (Chrome, Edge, or Firefox installed locally), you are exposed to zero-day exploits that Microsoft will never patch. duckduckgo browser download for windows 81 portable
If the above is too complex, use and set DuckDuckGo as default search: There is currently no official portable version DuckDuckGo
Brave offers excellent tracking protection, though you must seek older standalone builds to run it on Windows 8.1. or Firefox installed locally)