This is a weird problem I encountered a week ago and thought I would share it. Apparently, some security software was removed from this person’s computer and it broke the network stack. It was McAfee I believe. In any case, here were the symptoms:

• No network adapters were listed in the Task Manager -> Networking tab
• An ipconfig resulted in a blank listing – just “Windows IP Configuration” and no numbers or adapters shown
• In the device manager, all network items have the “Yellow Exclamation point”, and they have a hyphen “-” after their names
• WAN Miniport (IP) was also listed in the same manner

Here’s how I fixed it:

• Make sure Device Manager is closed
• open regedit, find the following folder, back it up then delete it
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\MS_PASSTHRUMP
• Go back into device manager and remove all network adapters
• do a device refresh… or reboot.

That fixed the problem for me. Hopefully this helps someone else!