Connecting two monitors with two video cards

I have an onboard video card (amd radeon Hd graphics 4200) and a pci express (amd radeon Hd 3500(i think)) I currently have Windows 7 installed. I have my main monitor hooked to the card itself. My other monitor is hooked up to the integrated graphics. The problem is that my computer does not detect my secondary monitor.. Both monitors work and both graphics work. Also all my drivers are up to date.

 

I have found the same with newer systems. When a PCI card is installed the intergrated graphics are disabled automatically. You might look in the BIOS and see if that can be changed. The Dell I tried this with came up with a message in BIOS telling me this would not work.
Older systems I had no problem using intergrated and a video card at the same time.
Why did they need to 'fix' that?

 

So i got both the monitors working with two video cards
How i did it not sure lol but i will try to explain it to the best i can.


I right clicked and hit "AMD VISION Engine Control Center" clicked on the "Performance" Tab, and it opened. I proceded to hit "AMD CrossFireXtm" I disabled it and both monitors turned on.

 

I think it depends on the BIOS of the machine. I tried on two machines with Nvidia cards and couldn't get it to work. If I started with onboard the Nvidia control panel wouldn't open but just gave a message about no Nvidia card present. If I started with the card, i found no way to get the onboard started using Win7 controls. I think goomma got lucky!

From my tinkering, I would have suggested getting an adapter so one of the monitors could be attached to an unused video output on the card which is probably the solution for most people judging from the responses.

I too am glad to learn that you can use both on some systems.