How to disable IPv6

Here are step-by-step instructions for how to disable Internet Protocol version 6 (IPv6) or its specific components in Windows 7, in Windows Vista, in Windows Server 2008 R2, and in Windows Server 2008.

1. Open registry editor (regedit or regedt32)
2. In registry editor, locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters \
3. If exists, double-click DisableComponents. If it doesn't exist you will need to create it.
• Type = DWORD (32-bit)
• Name = DisabledComponents
• Data = ffffffff (Hex - 8 f's)
4. Exit regsitry editor and reboot PC

Here is a list of all available data values:

• Type 0 to enable all IPv6 components. (Windows default setting)
• Type 0xffffffff to disable all IPv6 components except the IPv6 loopback interface. This value also configures Windows to prefer using IPv4 over IPv6 by changing entries in the prefix policy table. For more information, see Source and Destination Address Selection.
• Type 0x20 to prefer IPv4 over IPv6 by changing entries in the prefix policy table.
• Type 0x10 to disable IPv6 on all nontunnel interfaces (both LAN and Point-to-Point Protocol [PPP] interfaces).
• Type 0x01 to disable IPv6 on all tunnel interfaces. These include Intra-Site Automatic Tunnel Addressing Protocol (ISATAP), 6to4, and Teredo.
• Type 0x11 to disable all IPv6 interfaces except for the IPv6 loopback interface.

To use the DisabledComponents registry value to check whether IPv6 was disabled, run the following command at a Windows command prompt: 

reg query HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters /v DisabledComponents