OK, I have a Dell Optiplex 755 and on the back there is only one VGA video card port, but I am trying to connect two monitors and set one monitor up as the primary while using the second monitor as a extended view for the desktop of my primary monitor. What I have done is purchased a vga splitter cable with hopes of being able to set the monitors up the way I described above. First, I connected the vga male splitter cable into the vga video card and then connected one female cable end to a vga cable that is connected to a monitor and then connected the other vga female cable end into the vga cable for the other monitor. I noticed right away that both the monitors were on, but the display was showing the same desktop for each monitor. I don't want a duplicate of my desktop showing on another monitor I want to make one monitor an extension of the other monitor so I can have more room for my desktop. I tried changing settings in the display settings, but no matter what I do it just shows one monitor cloning what the other monitor has. When I click on identify it shows both monitors as being number 1. I have a feeling I am either going to have to add another vga video card or a dvi-d card? Can anyone explain to me why the vga splitter cable won't work?