How do i delete the excess windows system?

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Today,when i wanna recover my windows system,i can't find my image file in my computer and it's fail. So i installed my Ghost software and i don't know whether i install it before.But then,when i recover my windows system again,the image file still seems disappear yet.What's worse, another windows default is increased in the start screen of my laptop,but i can't get in with the increased windows default ,for the windows root\system 32\hal.dll is ruined. At the same time,i find that my original windows system does work again,so the windows default is excess. How do i delete the excess windows system?I'm looking forward to your advices.