Tohiba lap top L 500-12T got stuck.

Hello,
My toshiba L 500-12T LOP TOP got stuck while connecting to the internet.i am using external modem( 56k ).
i am not able move my curser and i tried to close the system by switching of the machine, using cont+alt+del, and tried F1,F2 ECT. By any means i am not able to operate or close the system. it is still running. what i have to do.
i removed the windows vista and using windows xp.please help me to resolve the problem.why this thing happens?my machine is a brand new one.