When you connect to a web site, your computer is sent DNS -> IP resolver data from your DNS (Domain Naming System) server.

This data is stored in a local data cache on your machine so that when you go to a web site more than once, your machine doesn't have to ask for that location every time.

The OS stores these results in a local DNS cache so that local clients don't repeatedly query the DNS server for the same address. These DNS cache entries are known as DNS Resource Records (RR), and the DNS resolver always checks the local cache before it queries the DNS server.

Copy this text below and paste into notepad, and save it as it dns.reg, right click on the saved file and choose "Merge"

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Dnscache\Parameters]

Or just download this ready made one below :

Download : DnsCache.reg

Once downloaded, right click the file and choose "merge", reboot

To view the current DNS resolver cache content and the entries preloaded from the Hosts file, go to the command prompt and type

x:\> ipconfig /displaydns

You can clear the DNS cache by this command:

x:\> ipconfig /flushdns

Fonte: Ntfs.org