Whenever posting questions on these forums, please give us as much information as possible about the computer. The operating system, processor speed, amount of RAM installed, brand name of the computer (if there is one) and any EXACT error messages that you are seeing. The more information you give us, the better informed our answer will be. Enough of that, back to your question.
Do you mean 'Device Manager', or 'Task Manager' and how are you seeing this 'Network Controller' listing? A 'Network Controller' assists with the Ethernet card's ability to work. Helps with computers that have the ability to be 'servers' or work on networks.
If you're seeing a yellow question-mark next to the 'Network Controller' and it's having conflicts of some sort. Are you having internet/network connection difficulties?
Hope this helps.
In my Task Manager the Network Controller is yellowed out