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#11
Now see if you can plug back in the hard drive alone to Clean Reinstall Windows 7 . THis would mean the DVD drive is blocking boot.
If the HD continues to block boot itself, then you'll need to replace it or slave it to another PC to wipe it with Diskpart Clean Command clear the boot code that's interfering, then do a full format in Disk Mgmt before returning it to PC.
If you cant slave it to another PC, its possible you can wipe it from Command Line in System Recovery Option but if it will boot into installer to do that then it should proceed with install from the drive selection screen where you can delete all partitions, create and format new.