I have a problem with my Mini DisplayPort to VGA Adapter working when I have it plugged into the back of the display.

I have a windows machine that I am trying to use with my Cinema display. I am using a Mini DisplayPort to VGA adapter. When I have everything plugged in nothing shows up. I have also tried using a Mini DisplayPort to DisplayPort cable but that does not work either.

Any information to why none of these work please let me know.

Thanks!