If you can't change resolution, the driver isn't active. Check Device Manager to see if the card is recognized. If you'd like, I can help you:
This often indicates a hardware failure (overheating) or a driver conflict. Try the DDU tool mentioned above. 9800 gtx draiver skachat
Restart your PC to finalize the graphics acceleration. ⚠️ Important Compatibility Notes If you can't change resolution, the driver isn't active