Cannot uninstall tools for external file operation

Hello,
I cannot uninstall daemon tools lite which shows active in my task manager menu. I have tried to uninstall it but it shows failure or to be specific the pc hangs when I try to uninstall it. It really is causing some CPU process and I need it to be Uninstalled soon since it goes not automatic start up on restart.
Kindly someone help me out of the problem.
Arnold Huang
