Without looking to deeply into Google I can tell you that you are looking for something that probably doesn't exist. If it has to be Vista compatible then it will almost certainly be PCI-e. Why would a graphics card manufacturer create something for a brand new operating system with an out-of-date interface?
What I don't understand is why a virtually new PC (I assume it's new as it's running Vista) has only got one PCI slot. Or is this an old PC that you are trying to upgrade?
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Do you know that we're all in line for succession to the throne? Really?
Well, if forty-eight million, two hundred thousand, seven hundred and one people died I'd be Queen.