Your PC or Laptop Domain Name System (DNS) cache stores the locations (IP addresses) of web pages you have in recent times open in your browser. If the location (IP addresses) of the web page changes in very recently than the entry in your Domain Name System (DNS) cache is updated, you will be not be able to access the web page of your website.
If you are encountering a high number of HTML 404 error codes, you may need to flush your Domain Name System (DNS) cache. Once you clear your Domain Name System (DNS) cache, your computer will query nameservers for the new Domain Name System (DNS) information you require.
If you would like to get more information about the HTML 404 error code, please visit the HTML 404 article on wikipedia.
The procedures detailed below allow you to remove old & wrong Domain Name System (DNS) info that may result in 404 errors web page.
For Windows® XP, 2000, Windows® Vista® or Windows ® 7 Operating system.
> Open the Start menu.
> Go to the Run.
> If you do not see the Run command in Windows®Vista, or Windows ® 7 search for “run” in the Search bar.
> In the Run text box please type: ipconfig /flushdns
> Now finely Press “Enter” or Return, and your cache will be flushed.
For MacOS® Operating system.
> Go to the Applications.
> Go to the Utilities.
> Open the Terminal application.
> Type: dscacheutil -flushcache
> Now finely Press Enter or Return, and your cache will be flushed.
Domain Name System (DNS) changes are not instant. It takes 24-48 hours for the Domain Name System (DNS) settings to propagate to the millions of internet provider routers and nameservers on the internet. To speed up the internet, ISP (Internet Server Provider) caches their Domain Name System (DNS) records. They create their own copy of the master record and access it locally to search for website, each time someone tries to view it. This procedure speeds up the internet, reduces the traffic and thus help ISP work faster.
Every ISP ( PTCL broadband , EVO, Wateen, Qubee etc ) caches Domain Name System (DNS) record and update it each few days. Each ISP has their own standard time frame to update the cache Domain Name System (DNS) record. This delay from your ISP will prevent you from viewing the changes. This process is known as Domain Name System (DNS) propagation delay. The slow updating of the server cache is called propagation. The Domain Name System (DNS) information for your domain gets propagated across all servers on the web.
For this reason, you might encounter the issue for the next few more hours. After completing this propagation, it will be resolving fine from everywhere.