Firefox assumes that all phrases that make use of a period are web addresses and will try to load them. This can be quite frustrating if a user wanted to look up a file name in a search engine. You can test that yourself by entering svchost.exe in the address bar. Firefox will try to load the website svchost.exe even though the .exe domain extension is not existent.

There is no Firefox setting or add-on that can restrict the extensions to the known domain extensions but there is another way to directly saerch for terms with periods in Firefox using the location bar.

All that is needed is to place a “?” before the search term. While a search for svchost.exe would result in a page not found error in Firefox a search for ?svchost.exe would perform the search in the default search engine and deliver the desired result.