Could you check the default search engine setting to see whether you can select DDG there? If it's not on the list, scroll down below the "Search shortcuts" box and look for the "Restore default search engines" button. Does that bring it back? See: [[Change your default search settings in Firefox]] If the problem is that DDG is selected, and while you are typing your query Firefox says it will use DDG, but then search results appear on some other site, this kind of hijack can be caused either by a rogue extension or by external malware. You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either: * click the Extensions button (puzzle piece) on the toolbar > Manage Extensions * Ctrl+Shift+a (Mac: Command+Shift+a) * "3-bar" menu button (or Tools menu) > Add-ons * type or paste '''about:addons''' in the address bar and press Enter/Return In the left column of the Add-ons page, click Extensions. On the right side, find the "Manage Your Extensions" heading. ''If there is at least one extension before the next heading -- "Recommended Extensions" -- please continue:'' Then cast a critical eye over the list below that heading. Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything suspicious or that you just do not remember installing or why? If in doubt, disable (or remove). For your privacy and security, don't let mystery programs linger here. Any improvement? ''Note: Sometimes extensions can frustrate access to this page. In that case, first restart Firefox in its Troubleshot Mode and then try again.'' See: [[Diagnose Firefox issues using Troubleshoot Mode]] -- Open, not Refresh.