I assume you installed Windows 7 while the SATA drives were set to RAID mode.
You try enabling the AHCI mode on your boot drive: http://superuser.com/questions/110927/how-can-i-enable-ahci-on-a-sata-drive-after-installing-windows
After enabling AHCI mode there should be no problem booting with the BIOS set to AHCI.
Then you can connect your faulty drive to your PC and see if it appears.
I believe that I am closer now because if this change but the drive is still not showing up. It does cause the bios to hang when it is connected now so I can't boot with it connected.
I think I changed XP to AHCI mode in order to use the 2 and 3 tb drives long ago so everything should have been in AHCI. It seems like 7 changes the drive software when the ACHI is changed. It says that it is installing drivers on the drives when it is started and then wants a second reboot. This might indicate that the drivers were changed to RAID by 7 after it was installed. I wonder if the change damaged the software in that drive at some point?
I have to knock it off for the night. Can the software in the drive be changed or repaired without erasing it or can the data be transferred to a functioning drive if 7 can't see it?