Hello. My name is Michael. I can help you with your question.
Can you please explain the symptoms in more detail? What problems are you having?
One initial suggestion I have is, if you cannot get online with IE, download Chrome, at least for now, so you can get online. Of course, if you cannot get online with the system you are trying to fix, you would have to download chrome to a different computer, copy to a flash drive and then run the setup on the computer with the problem.
The windows 10 downgrade to Windows 7 is supposed to revert all changes so the computer is as it was prior to the upgrade. Were you having any problems before the upgrade?