No network on reboot - Connection Details for Adapter Blank/Empty

Question

I've been dealing with this issue for over a week now, and while extensive Internet searches have found similar situations, none exactly matched my situation, and none of the suggested fixes had any positive effects. Here's my exact situation:
1.) System Specs:
OS: Windows 8 Pro
CPU: 3.60 gigahertz Intel Core i7-3820
RAM: 64GB DDR3 -1333
Disk Space: 2.6TB on 4 SSD and 2 HDD
Network Adapters: (2x) Broadcom NetLink Gigabit Ethernet
2.) On computer startup (whether cold start, warm start or "forced" reset), when I get to the lock screen, the network icon has the
dreaded "yellow triangle" overlay displayed. I can log in using my Windows Live credentials with no problems, but that same warning overlay is on the network icon in the taskbar, as well, and I have absolutely no WAN
or LAN access. Both network adapters show up in Network Connections as enabled (as opposed to disabled or "network"), and when I double-click either one (or if I right-click and select Status), I get the status popup, but it's completely empty. And
by that I mean nothing at all is displayed in the main section. In order to get my network connection up and running, I have to disable at least one of the adapters and then enable it. Once that's completed, I have both Internet and LAN connectivity, but if
I reboot for whatever reason, it all goes away, and I have to do the same dance once more.
3.) Things I've tried (not necessarily in order):
a.) uninstall/reinstall NIC drivers, using not only current, but also "next-gen" and "last-gen" versions - no help
b.) Disable or uninstall one or the other of the NIC's - also no help
c.) Disable IPv6 on one/both adapters - foolish, I know, but it was suggested, so I tried it - no help
d.) install the "original" Windows 8 native drivers - no help
e.) Created a logoff script to disable the adapters, and a startup script to enable them - no help (though manually running the same instructions from
an elevated command prompt does work, but it's faster to disable/enable them from the Network Connections window - and yes, I made sure that the shutdown/startup scripts had admin access - I
just think they were being executed at the wrong stage of the boot process)
f.) Ran SFC /scannow from an elevated command prompt - no errors found
g.) Checked the event viewer for information regarding this issue, and nothing shows up - not even "information" entries.
h.) Ran System Restore to a date/point before this first occurred - no help
Now this isn't my first rodeo with networking errors, and while I'm certainly no "IT Guru", I like to think I know my way around the tech well enough to be able to suss out the vast majority of networking issues, but
this one has me stumped. This is a reasonably new system for me, having purchased/built it back in March, but it's also a "2 generation" upgrade over the old box, so there are no "known good" replacements available to try. Also, one NIC
is built into the MoBo, while the other is in the PCIe sound card. Both came as a "package deal", and are supposedly cross-compatible with each other (ASRock assures me this is true). I also didn't bother testing the cables, routers or modem, since
this appears to be a software or driver problem, and I'm leaning heavily toward it being with the driver, somehow.
Well, that's my dilemma. I tried to be as complete as possible with the information, but as I'm only Human, I may have missed something. I'm more than happy to provide any other information that may be necessary. If anyone has any ideas about something that
I may have missed (short of a full wipe/reinstall, of course - that's just below initiating Global Meltdown on my priority list), or knows what may be causing this, I would greatly appreciate the sharing of knowledge. :)
Safe, Reliable Insanity, Since 1961!

Answer 1

Ok, as an update, I've tried a couple of different things, none with any permanent success, but with some interesting consequences:
1.) Using Task manager's Startup tab, I've disabled all entries listed and rebooted - no help (cards still fail to initialize)
2.) Through msconfig, I disabled all non-Microsoft services and rebooted - no help
3.) I tried both items 1 and 2 combined - also no help
4.) Rather than altering the Speed/Duplex settings on one of the network cards, I attempted to change some of the other settings (one at a time, of course) to a non-default value, and each time I met with the same result. The affected card initialized, and
connected to the internet, but a reboot again saw that card in a state of failed initialization. And it doesn't matter which network card I alter, as both individually behave in this manner.
My (tentative) conclusion at this point, given all that I've seen so far is that something "out of the ordinary" is causing this issue, and that it's entirely possible, if not likely that it's a Microsoft service or startup file that's causing this behavior.
At this point, I'm tempted to refresh my computer, but the list of installed applications on this box is huge, and it will take me several days to nearly a week to get everything reinstalled, so I'm trying to keep that back as a last resort, if at all possible.
So before I break down and do that, is there anything else that I might have missed?
Safe, Reliable Insanity, Since 1961!