When a domain name’s nameservers change, it can cause an annoyingly long wait until the website becomes accessible again.

Apart from your ISP having to refresh the DNS cache on their servers , other issues on your local PC can also cause DNS problems

Sometimes a reboot is sufficient, but there is a quicker way of solving the problem.

By using the command line utility ipconfig, you can force Windows to clear its DNS Cache.

The DNS cache holds a record of all the websites you have visited and their IPs, so the next time you request a website, Windows looks in its DNS cache. The cache is deleted every 24 hours. However, if a website’s DNS information has changed more recently than that, or the cache has stored a negative response (due to a high level of network congestion or server load) the cache becomes outdated and can lead to browsing problems. Follow this simple procedure to clear your DNS cache:

Go to Start, Run and enter “cmd”

Type “ipconfig /flushdns” into the command prompt.

Press Enter. You will be informed that your DNS cache has been cleared.

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If you experience problems refreshing the cache you could also try the following commands in the stated order(press enter after each command):<br />
ipconfig /release<br />
ipconfig /renew<br />
ipconfig /flushdns<br />

The procedure is mainly the same in both Windows XP and Vista, apart from you must press Ctrl + Shift + Enter in the command prompt under Vista so as to activate administrative priviledges.