Starting in WindowsVista and Server 2008, Microsoft includes native support for IPv6(Internet Protocol Version 6) and is enabled by default.  IPv6 is thenew computer address protocol that will eventually replace IPv4 whichis currently the most popular standard. Unless you network has aspecific requirement for IPv6, very few do, you can safely disableIPv6. Unlike other protocols, you cannot disable IPv6 by disabling theprotocol on each of your network interfaces. While that will disablethe protocol for the interfaces the loopback and tunnel interfaces willstill have it enabled that can cause problems with applications.  Theproper way to disable IPv6 is to disable via the registry.

First, click on the Start Button and thn RUN (or you can directly access RUN via pressing Windows Key + R) type in regedit and hit Enter.

Then,navigate through

HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/services/TCPIP6 and Parameters

Right click on Parameters and selectNew and then DWORD (32-bit) Value.

Name the new valueDisabledComponents and hit Enter.

Now right click on the newDisabledComponents value you just created and select Modify.

Set thevalue of DisabledComponents to FFFFFFFF and click OK.
After a reboot IPv6 will be disabled on all interfaces.

Thanks...