Windows 7: Install issue with RC 64bit

ok


i have 4 HDDs, 1 is IDE 3 SATA

1 SATA has 2 working OSs on it, one has never had an OS installed on it, and 1 has had an OS installed, and it has been reformatted and then the space has been unallocated


the IDE dtive has a corrupted install of windows




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the drive that has never had an OS installed wouldnt let me install on it, i think cuz there was no free space at the head of the disk, the second partition was the one that was free, and no matter what i tried it wouldnt let me install on that partition...

reformatting that drive is not an option, so i decided to try one of the other 3


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when i try to install windows 7 the IDE with a corrupted OS gives me a windows failed to start error, and says a system registry file is missing, same thing happens with the SATA drive that has 2 working OSs, which leads me to think that it may have something to do with previous 32 bit installs (im trying to install 64 bit 7) rather then an actual registry error


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so the SATA drive that i reformatted and unallocated...

same thing happens, a registry issue

now i assume that means its still got something in the MBR telling it theres a windows install on it, and i have no idea how to delete that...



is that most likely the issue?
how could i delete the MBR?