I wouldn't have thought that an AMD GPU would have a Nvidia Controller.
Windows may have installed it in error during the upgrade.
Click on the Start button - Settings - Update & Security - Windows update - Advanced options - View your update history.
Did you create a full system image before upgrading from Win 7 or you can use the revert option if you haven't removed Windows.old.
I would advise creating a full system image of what you have now - on different media if using an external HDD then do the upgrade again.
While the free upgrade to the general public has expired, MS have extended the upgrade for those using Assistive Technologies - whatever they are and as long as you say you are, you can use the Upgrade now button to do a fresh upgrade.
MS don't check to see if you are, but I suspect this could be a ruse to get more people onto Win 10 who may have missed the deadline - could be wrong though as I'm sure MS aren't as devious as that
You can read the full article at
http://www.ghacks.net/2016/07/29/you-can-still-grab-a-free-windows-10-upgrade-after-july-29-2016/Clicking on
launched hyperlink in the article will get you the upgrade now page -
http://www.microsoft.com/en-us/accessibility/windows10upgradeIf you Upgrade now over the existing Win 10 install, you will not be able to use Win 10's revert to the previous OS.
Not sure how you upgraded but if you used
https://www.microsoft.com/en-gb/software-download/windows10 I think you can still use the MCT to create a Win 10 bootable USB or disk - not sure if the Upgrade now will still work on that page though.
MS have said they will update the MCT after the 2nd Aug. update so newer bootable media can be created.
I used
https://www.microsoft.com/en-gb/download/windows-usb-dvd-download-tool to create a bootable disk, but this program also gives you the choice of disk or USB