1. How to Fix 404 Error?
404 Not Found error messages are frequently customized by individual
websites, so keep in mind that the 404 error may show up in just about
any way imaginable depending on what website it's shown from. Here are
some common ways in which you might see the HTTP 404 error
displayed:
"404 Error"
"HTTP 404"
"404 Not Found"
"Error 404"
"Error 404 Not Found"
"The requested URL [URL] was not found on this server."
"Error 404 Not Found"
"404 File or Directory Not Found"
"HTTP 404 Not Found"
Cause of HTTP 404 Errors
A 404 error is an HTTP status code that means that the page you were
trying to reach on a website couldn't be found on their server. Technically,
an Error 404 is a client-side error, implying that the error is your mistake,
either because you mistyped the URL or the page has been moved or
removed from the website and you should have known. Another
possibility is if a website has moved a page or resource but did so without
redirecting the old URL to the new one. When that happens, you'll
receive a 404 error instead of being automatically routed to the new page.

2. How to Fix the 404 Not Found Error
Retry the web page by pressing F5, clicking the refresh/reload button, or
trying the URL from the address bar again. The 404 Not Found errors
might appear for several reasons even though no real issue exists, so
sometimes a simple refresh will often load the page you were looking for.
You might also consider clearing your browser's cookies, or at least the
one(s) involved with the website in question, if clearing the cache didn't
work. Clear your browser's cache if you have any indication that the 404
Not Found message might just be yours. For example, if you can reach
the URL from your phone but not from your tablet, clearing the cache on
your tablet's browser might help.
You can download Smart 404 Not Found Fixer Pro here.
http://www.lionsea.com/download/fixer/Smart_404_Not_Found_Fixer_P
ro_Setup.exe
Just run Smart 404 Not Found Fixer Pro, click 'quick scan'
After the scan is completed, click 'repair all' button.
http://www.lionsea.com/