You might have heard about IPv6, it is the latest address protocol that will eventually replace IPv4. From Windows Vista onward it has been kept enabled by default, but it is also a fact that IPv6 is not yet common and many software, routers, modems, and other network equipment do not support it yet. So it may be a wise approach to disable it for now. We can also disable it by simply unchecking it from the Local Area Network Properties window, but this is not a permanent way to get rid of it. It gets enabled again once the system is restarted, so in order to permanently disable it, open the registry editor in Windows 7 & Vista by clicking Start, then type regedit and hit Enter.
Once it is launched, navigate to HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > services >TCPIP6 > Parameters key.
Now right-click Parameters in the left sidebar and choose New > DWORD (32-bit) Value
Here name it as DisabledComponents, set the value of DisabledComponents to 0 and click OK.
That’s it, now restart your computer and IPv6 will be disabled permanently.