I would download the newest drivers but not install them. Then I would boot into safe mode and remove the unknown device, sound devices and network adapters in Device Manager. Then I would reboot in Windows normally and let it find the devices again. I would then update the drivers as needed.
If that doesn't work then we need to find out what the unknown device is as it's probably causing all of your problems. Go into the bios and disable the built-in devices one at a time until the unknown device disappears. Once we know that we can decide upon your next best option.