Windows Loading Problem / Black Screen

Hello,

One day all of the sudden when I start my machine the bios flashes as normal, Wiindows XP Pro loading screen comes up fine and the progress bar is fine and then the screen looks like it is going into the Welcome/Log-In screen but the screen stays black but I can still see my mouse pointer.

I tried sfae mode and it is the exact same thing.

please helpppppp.