Did you try using the Windows 7 graphics driver in the Windows 10 install? Windows 10 supports using Windows 7 drivers.
In the case of graphics drivers, you will loose some Direct X 12 features (although not all) by using a Windows 7 driver but if the graphics chipset is that old, it probably wouldn't support the new features anyway.
If the graphics manufacturer has released a Windows 10 driver but it doesn't work for some reason, then you may have to boot Windows 10 in safe mode to force the use of the older driver. However, once that is done things should work. When you force a driver install in safe mode, Windows 10 appears to avoid automatically updating the driver in the future, which is nice.