Simon, you could just check what video card you have on the PC from video properties, you should be able to work out what type of output you have from that?

The adapter/converter (for VGA to digital) has the four pins in a square to the left, with a horizontal pin as wide as the 'square' of the 4 pins, plus 12 of the other 24 possble pins present.

Just to add I don't actually use my adapter/converter, they just came with the screen/PC (video card is a dual screen one).

EDITED: cos my speeling was crap