Dual Monitor help

Having issues with my computer not detecting my second monitor. My Primary is connected to hdmi cable (Video and Sound). The second monitor I hooked up with an DVI cable and shows nothing. Try hitting the detect button and it says Another monitor not detected. When I pull out the HDMI cable the DVI detects the second monitor and switches it to the primary.

 

It would help to know your computer configuration. OS, video card, 32 bit or 64 bit, etc...

 

Yep, knowing the model of video card would be good. Sounds like those are not 2 independant ports - you get to use one or the other. The card only has those 2 ports?

Model? plz.

 

It's Windows 7 64 bit, using my motherboard graphics which is a NVIDIA GeForce 8300. Using two Dell ST2421L 24" monitors. It lets me dual monitor if I have one DVI and one VGA, but when I have one connected to HDMI the DVi will not detect anything.

 

Will it work if you use HDMI and VGA? The card may not have enough oomph to run both higher outputs at the same time.

 

like I said in my post it is posible that those are 'technically' one port.. more searching found.
"The cards typically have a limited number of "digital clocks". The ION may only have a single digital clock and an analog clock. This being the case, you can do a digital connection and an analog simultaneously, but not 2 digitals."

When you boot up are both displays working? showing the boot.