If you cannot find drivers for the new Windows 10 specifically from your device manufacturer (and GPU manufacturer if you have one installed), it is my own humble opinion that the system not be upgraded. Chances are the internal computer hardware was created specifically for older systems, and upgrading runs the risk of stability or speed issues in the future.
The choice is yours, but my own experience tells me driver problems are a major headache personally.
Is there anyone here who knows they have drivers provided by their computer/motherboard manufacturer online specific for Windows 10, but are still having issues upgrading? Because those people my have success following these tutorials on the old operating system before upgrading:
DISM - Repair Windows 10 Image - Windows 10 Forums
SFC Command - Run in Windows 10 - Windows 10 Forums