Based on your description, I recommend you doing the following:
- Uninstall the current driver you have installed.
- Update the other drivers from your system manufacturer site, including the BIOS.
- Download our generic driver from our side at the following link:
Since you have two graphics card in your system, means you® computer has a special configuration called Switchable Graphics. I recommend you doing the steps above and if issue persists, you may contact Dell to get their specific drivers that were designed for your unit.