In computer network communications, problems such as error 404 not found, the HTTP 404, page not found, or filename not found warning message are common. Hypertext transfer protocol (HTTP) error codes indicate that although the browser was able to communicate with the desired server, the server was unable to locate the requested resource. Your browser's cache should be cleared if you suspect the 404 message is yours. Adjust the PC's DNS servers, but only when a whole website is returning you a 404 error, particularly if the page is accessible to individuals on different networks. Reattempt the web page by hitting F5, pressing repeatedly the refresh button, or entering the URL again into the address box.