Hard Drive with MBR Failed; how do I get main installation working?

My former hard drive with my MBR on it failed. This hard drive was/is 750GB and when I purchased my 'main' 2TB hard drive I made another fresh install of Windows. In other words, I had two installations of Windows on two separate hard drives. However, the MBR is located on the now-failed 750GB hard drive, and so my 2TB install of Windows won't work. I have tried (and failed) at repairing or otherwise installing a new MBR on the 2TB hard drive. I am at a loss at what to do. Perhaps I am missing something big or am making a small oversight, I really don't know. Help appreciated! :)

If there was no MBR on the 2tb HDD drive, Windows would not install.

For old 750gb HDD drive
Check the hard drive with the manufacturer's diagnostic tools.
Hard Drive Diagnostics Tools and Utilities (Storage) - TACKtech Corp.
Hard Drive Diagnostic Procedure

Startup Repair will not work to write the System boot files to the remaining Win7 partition unless you mark it Active first:

First Mark Partition Active, then run Startup Repair - Run up to 3 Separate Times until Win7 starts and holds the System Active flags showing the boot files are onboard.

Thank you so much for all your help. I tried everything you guys told me, and when it came down to it gregrocker's method got my system up and running again. Marking the partition as active was the main hurdle I was having problems with. Thanks!!

From what I've seen if the Active flag is not on the partition, Startup Repair will not work until you mark the intended boot partition Active showing it where you want the boot files repaired or written.

Interesting.