Running two bootable drives makes one permanently unbootable?

[Newmaven]

I am just finishing a clean reinstall of EVERYTHING onto a new drive. I had hoped, once I'd installed Win 7 Pro x64 in the new drive, I'd be able to put the other drive back in the system to transfer certain files. But every time I did, it rendered the new drive unbootable, even after I'd taken the old one out again. I'd still like to be able to transfer files directly between them -- is there any way I can?

 

[MilesAhead]

The boot partition on the old drive is likely marked as active. If you have a docking station or usb enclosure you could plug into a usb port then use Disk Management to remove the attribute.

Apparently diskpart command can do it:
http://www.sevenforums.com/hardware-devices/232286-remove-activeportion-harddrive.html

Just be careful when you select the disk to put the right number or you can hose the system disk.
When you do list disk
it shows all the disks on the system.. just be sure to get the right one.when you select disk.

 

[gregrocker]

Also check which drive is set to boot first in BIOS setup when you plug back in the other drive. It needs to be the new one. Sometimes you must set the HD priority itself.

Once you get it booted with all drives attached post back a screenshot of Disk Management - Post a Screen Capture Image