1-While monitor is connected to graphic card PCI/AGP, power ON then press Del or F1 to open BIOS menu. Look for the setting on graphics priority. Make the motherboard's integrated graphics as priority or initial display. Save and exit. Move monitor connector to integrated VGA port of monitor.
2- A less BIOSy version would be to go to your desktop and right click the desktop then go to the properties and click the Color/resolution tab you should have the choice of two video outputs to adjust. Choose the one that is built in and click the box that says "Extend my desktop to this one" then choose the PCI one and unclick the "Make this the Default/primary video output" then choose the built in and Check the "Make this the Default/primary video output".
Now, one thing to understand, when you put the PCI card in, and got it working correctly, your computer was forced to recognize that it would be the primary video output (controller). Anyways, you can use both, but the card is likely better.
You can reverse back to the card by doing the steps in the same order, just switch the card and built ins around.......Karz