Are you trying to use these as extended displays, or as 2D surround? 2D surround requires digital connections. If all you want is to use them as extended desktop displays, you will need active adapters, which aren't cheap, except for the DVI-I port. DVI-I supports analog, so get a normal DVI-I to VGA adapter. The HDMI to VGA and DVI-D to VGA require active adapters.