Larrers, the 800x600 thing just means the win10 update couldn't find a better video driver.
If your hardware is anything like contemporary mainstream, you can download and apply a proper driver after the update has happened.
That will include all nVidia and ATI from living memory, and most chipset embedded Intel too.
If you have something like a Matrox G200 from yesteryear, you're fsckd.
Either change the card, or revert to Win95