Disabling IPv6 on Windows 2008

1. In the register Editor, locate and the following key:
a. HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesTcpip6 Parameters
2. If the DisabledComponents key doesnt exist, please create it.
a. In the Edit menu, point to New, and then click DWORD (32-bit) Value. 
b. Type DisabledComponents, and then press ENTER. 
c. Double-click DisabledComponents.
3. Type 0xffffffff to disable all IPv6 components, except IPv6 loopback interface. 
This value also configures Windows to use IPv4 instead of IPv6 in prefix 
policies.