I realise there are a number of similar questions already posted but I haven't seen any where the DVI input involved has been DVI-D. I hastily bought a VGA to DVI converter, then realised the cable I'd bought was DVI-I, which wouldn't fit in my DVI-D port. From searching, I couldn't find any VGA to DVI-D cables. Is there any reason why I wouldn't or shouldn't be able to run dual monitors, with one monitor in a VGA port, the other in a DVI-D port? Thanks in advance for any help and apologies if this is very basic stuff!
The problem is that normal DVI has both analog and digital signal and the cheap "converters" only do mechanical conversion.
DVI-D is completely digital and you'll need a converter that will do analog to digital conversion and turn the VGA signal into DVI signal. They seem to be much more expensive but they do exist. It may be cheaper to just change video card or monitor from what I see. This was my first search result for keywords
EDIT: Actually, I'm not sure I got your question right....
You should be able to normally run two monitors with a video card that has DVI-D and VGA output (if the card supports that and from what I've seen, most do).
The next part of the problem are the monitors. I'm not 100% clear on what type of input they have.
If it's VGA, just connect it to the VGA port on the card.
If it's DVI, just connect it to the DVI port on the card using a DVI-D cable.
If the monitor has DVI-A, then you you'll need to get a VGA to DVI-A converter such as this one for example and connect monitor to VGA port.
If the VGA port is already populated, you'll need a DVI-D to VGA converter such as this one. Same solution needs to be used if you have two VGA monitors. Again it may be cheaper to get a suitable monitor or video card.
DVI-D Is a digital output, while VGA is just analog video. DVI-I <-> VGA is a DVI connector which just maps the subset of pins carrying the analog signal to an VGA connector. The best you can do is to get a new monitor whith a true digital DVI input.