Can someone please tell me why the green light on the front of the cpu is yellow and not green? im running windows xp. i cant turn it on or even use the comptuer. i need an answer asap, i am using that computer for schoolTypically this means a power supply problem, Is this a dell ?Highly likely that a rail has blown in the power supply unit, and now it cannot provide enough watts / AMPS to start then run the computer. unfortunately PSU's often take other components with them when they go, but check out if you can get a replcement, ACTUALLY measure the PSU box dimensions, then LOOK at the INFORMATION stuck on it, and then try for a replacement do not jump and get one as cheap as possible or you will just get the same problem if not worse again very soon.

named brands Zalman, Tagan, Hiper, Enermax, Cooler master, Seasonic, Akasa, Blue Storm, Jeantech I'm not aware of any CPU's with lights on them...
Do you mean the monitor ? ?
If so double check all your connections with the machine and monitor un-plugged from all power sources.
Then plug everything back in and try it again.I THINK he means the tower lot of people in my work also call it the cpu ?