Different NTLDR issue: caused by non-system hard drive

I am getting an "NTLDR is missing" message on bootup, but the origin of the problem is, I think, different from the other NTLDR problems I've see on on this and other forums, because it is not related to the main (system) drive. In fact, when I remove the problem drive -- the E: drive, or in other words not the system drive -- the computer boots up fine. I thought that perhaps that this two-year-old disk was dying or that there were some bad sectors, but I've checked the disk for errors in Windows 7 (Properties > Tools > Check for Errors) and have found no problem. I've also tried different cables and SATA ports, always with the same result. Finally, I tried a System Restore. My other hard drives run fine. And the problem drive reads just fine when I connect it through a USB 2.0 hard drive deck.

I would prefer not to play with the Windows 7 MBR since the system seems fine when I don't use the problem drive. So here are some questions:

1. why am I having this problem?

2. Does a non-system drive have its own boot record or MBR that could be causing this problem?

3. If so, is there some way of editing or replacing it?

4. Is there any other kind of fix that I'm not seeing?

Thanks.

Check your BIOS boot order.

Thank you both for the responses. Just as followup: boot order was not the problem, and the drive had not been used as a system drive. I used Testdisk to the best of my ability, but without success. I just ended up transferring the information to another drive and reformatted the problem drive, which seems to be working OK in a JBOD external enclosure.