I am guessing you're wanting to hook up your xbox to the computer monitor.
This is easy with the desktop computer's CRT or LCD monitor, though nearly impossible with a laptop (at least, without opening its case).
Microsoft offers (for the 360 only, not original) an xbox cable that connects to a VGA input, for use with monitors and televisions that accept VGA connections.
You can probably find this on ebay MUCH cheaper than buying straight from MS.
To date, I still have not found a solution for the original xbox; while I could get a component to VGA adapter, that would not work due to the lack of horizontal and vertical sync. At least, this is what I am told.
Does anyone know what I would need to hook my 360 to my desktop and my laptop. I know there are adapters, but I would like to know which would be best for use with both a desktop and laptop. My mother in law is a Jehovahs Witness and she is offended by the games that I play and I cant play games when she is home out of respect for my other half. I want to take the TV in the room but that would leave them with nothing to do, and I would like to play it on my laptop but I need some adapter for that. Any help would be great. I would really like what works best with a laptop.