Upgrading to Windows 10 removes NVIDIA driver and NVIDIA custom settings (SLI, custom modes, custom whitelist, etc.
After upgrading to Windows 10, it's possible that certain NVIDIA setting may be lost. These may include:
First, make sure that you have the most recent driver installed and have access to the NVIDIA Control Panel. If you have issues installing an NVIDIA driver or don't see the Control Panel, please see this article:
Once the NVIDIA driver is properly installed on Windows 10, you will be able to open the NVIDIA Control Panel and configure all of your settings.