I can't give you really ANY specific help as I don't have much of any experience with the what you have going on. I can however tell you that if it is an issue with drivers. You won't likely find resolution on that OS. AMD does no longer support Windows 8.1. You would need to update to Win 10 or back to Win 7 for current drivers.
I am not saying that that your issue is driver related either. I don't know enough about the hardware situation you have going on to offer good advice.
Hopefully someone with better knowledge will reply too.
Good Luck!