You have one monitor connected via VGA to the VGA port on your motherboard, and another monitor connected via VGA-to-DVI into the DVI port on the motherboard - is that correct?
The motherboard (according to this link; ASUS - P8H61-M LE) has a DVI-D input connection. This means that it only accepts a digital display connection, so using an adapter on a VGA (VGA = analog) will not work. You need to get a DVI-D cable to connect between your display and motherboard for it to activate.
Let me know if you have any other questions,