Sounds like your other GPU may be having problems. Which could mean it needs replacing. Have you tried updating the drivers? And does the system even recognize the other card?
Try this....
A. Uninstall, and then reinstall, the latest graphics card driver.
B. Make sure that your Nvidia graphics card is set as the default graphics card.
Here's the steps on how to set it to default.
1. Open the "Nvidia Control Panel".
2. Select "Manage 3D Settings" under 3D Settings.
3. Click on the "Program Settings" tab and select the program you want to choose a graphics card for from the drop down list.
4. Now select "preferred graphics processor" in the drop down list. (You can see what the automatic option is listed as global setting) If you want to use the dedicated graphics card, select High-performance Nvidia processor.
Once it is running on the right one, test the system again and see if the problem persists.
If it won't work, then again I say the GPU may be the problem.