Okay I have windows 7 on my pc and and I also know what this bootmgr is and why that is compressed. I do know that if I insert my windows 7 cd it will solve my problem. But the problem is I have lost the windows 7 cd. So now I am thinking of buying windows 8. But I dont know how will I run it with message showing up. Plus I dont mind formatting my C drive but I dont know exactly how will I do it. So my question is, is there a way to solve this problem without original windows 7 cd? And how do I format my C drive? And if I format my C drive will my other drives also lose its content? If yes then how to stop that from happening?