The one in the computer right now is the old style of disk drive, which isn't much difference, other than the fact that the one in it may be somewhat faulty, being an old piece of hardware.
It would be laggy if you're plugged into the single slot on the motherboard, which would be a VGA port, rather than the DVI port, which there should be an adapter in one of the bags I sent with it, the one with the manuals and whatnot. The port you should be plugged into is a white port, rather than a blue port (which you may already be connected that way, I can't recall if there was an onboard VGA port..).
Even if it does work, it still makes a difference to me, I feel like I've stolen from you guys.. It just feels wrong to have something that does not belong to me. Whether you're plugged into a monitor or a TV should not make a difference, all it is is an input output device, which would have no bearing on your game performance, other than something simple like the refresh rate, but I've gamed on TV's and monitors and they provide the same basic function, to display your video. Some may have a higher refresh rate, but the average person would never notice the difference.
Just make sure you're plugged into the graphics card (two white ports on top of each other with a plastic cap over them) and use the bottom port with the DVI to VGA adapter that came in the packaging. (god I hope I didn't forget to send that either..).
Let me know if you have any other problems and I'll be glad to try and resolve them.