windows update fails when isatap enabled

Hi there,

I'm using windows 8.1 pro x64 and encounter one problem.

My desktop has only one ethernet adapter, and I've disabled its ipv6 protocol. Insteadly, I use isatap tunnel to access ipv6 network.

The problem is that, if the isatap tunnel works, windows update will try to fetch updates via ipv6 and fail; while if I diable the isatap tunnel, windows update will work fine.

I wonder how to force windows update to use ipv4 access while isatap tunnel enabled.

Thanks!