Hmm, it would seem then that the probability that the network adapter hardware is the issue is rather low. The behavior of you systems is more probably an OS issue rather than a hardware issue per se. MS has been re-plumbing the black box of Windows for many reasons and boot-up timing could well be changing across various builds as their development work moves along. Thus, differing versions may be triggering different behaviors - especially where timing sensitive events are occurring...
This issue is ultimately for MS to triage...and end users to...wait for....