Windows 10 Driver issues

I've been having driver issues with a genuine Arduino Uno lately. I've done almost everything I've found on the internet that says it can fix it - reinstall the drivers, reboot my PC, point Windows to the right drivers, reinstall the Arduino IDE, install other drivers, etc. Nothing, save for a fresh reinstall of Windows 10, has solved the problem.

If I point to the original drivers, the Uno shows up under COM5, but with the annoying little triangle, and the IDE won't show COM5 as being a valid COM port (I have several BT COM ports, but those aren't important). It sends me the frustrating Code 10 error - that the device cannot start.

I have tried other USB ports and cables, I even tried it on another PC and it still wouldn't work. Even using a live Ubuntu disk wouldn't do it. The frustrating bit is this - it worked perfectly fine yesterday when I was confirming one of my extra boards (Adafruit's Stereo FM Transmitter board), but freaked out after I tried to use it to flash the bootloader to my Pro Trinket 5V, which has been iffy for a few weeks.

What can I do to try and fix this Uno?