Lights not working

When i create a light in my scene, it does not show up. the scene is still dark, and light it being emitted. I am using Unity 2.5 on Windows, when I do the same in Unity on the Mac, it works fine. I just create the light and it emits. But on the PC it doesnt seem to be working.

Any ideas?

Works fine here. More details on what are you doing, what’s your hardware, etc.