Web site to do a 404 error pages
 

Believe a lot of friends to 404 page is not new right, when access to the web page when something goes wrong, there's a jump page, tell your visitors access error, let him continue to start from the home page to browse. Do eye, is to make the flow don't direct loss, so that it can hint visitors to visit, and a function is to make the spider from 404 pages, return to the home page crawled new content, so as to reduce website popup rate carry high site PV and user experience degree.

Not Found - The server was unable to locate the URL.

Some content management systems send 404 status codes when documents do exist. Ensure files that exist do give a 200 status code and requests for files that do not exist give a 404 status code. You may also want to check with your host to see if you can set up a custom 404 error page which makes it easy for site visitors to

view your most popular and / or most relevant navigational options
report navigational problems within your site

Search engines request a robots.txt file to see what portions of your site they are allowed to crawl. Many browsers request a favicon.ico file when loading your site. While neither of these files are necessary, creating them will help keep your log files clean so you can focus on whatever other errors your site might have.

404 error is very bad from SEO perspective. If you do have missing pages in your website then search engines mark your website down. You must prevent 404 error buy fixing them through robots.txt OR no follow. You can apply these methods on the page which has been removed by you. After it search engine will ignore this page and it will not be shown in the listing of SERP.

i find the error in most of the forums