I installed an ADD2 adapter card with a DVI-D input to run a second monitor display. The monitor is analog with only VGA connection. I have it connected with an adapter (DVI-D to VGA) but it is not recognizing the monitor. Are they incompatible?
The "D" -- after DVI -- stands for "digital" which means the card can only output to a digital display. The output of the ADD2 card would need to be a DVI-A (Analog) or DVI-I (Integrated; both Digital and Analog) in order to be compatible with an analog display. Visually, there are four pins around the broad "C5" pin on the DVI-I/A port that carry the analog signal which are absent on DVI-D. The cable being used should also resemble the desired connection.