RE: ATI Radeon Xpress 200 Series not compatible with Windows 10. Contact display manufacturer
That's the integrated video, not the monitor. Post your model computer when asking a question.
Sounds like you have really ancient graphics from almost 10 years ago. If it is on an ancient computer, stay with the OS that is working and wait to get windows 10 on a new computer. The old computer with integrated graphics doesn't meet the requirements for windows 10. Also you do not qualify for the free upgrade if you don't have windows 7 sp1 running on it.
I'm surprised you can even run that monitor with a decent resolution. Monitors are plug and play and don't need drivers, but you can get a much better picture with a better computer and a separate video card.