Do you want to disable IPv6 on all interfaces but find that doing so on the NIC properties in the GUI does not always work properly?

The best way to truly disable it is via registry setting:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters] “DisabledComponents”=dword:000000ff

This will disable it on all interfaces and force IPv4 preference…