This is why you should unplug all HD's except the target HD during install, and why the OS HD should be in DISK0 slot so that it can't have it's System files derailed to a data partition which is incorrectly marked Active.

You'll need to mark E Inactive using DIskpart command from Win7 Command Line:
Elevated Command Prompt
Partition - Mark as Active

Then in Disk Management mark Win7 partition Active as it should be.