A year ago, I did a fresh install of Windows 7 on a second hard drive and installed all my normal programs. It worked fine afterwords and was bootable and I set it aside. My idea was to be able use this drive (or to clone it) at any time I wanted to start over with a fresh install or in case of a failure of my primary drive, rather than having to reinstall windows and all the programs again. Then all I would have to do would be to move all my backed up data to the new drive.
Now I am in that situation, but this drive now is not bootable. I can see all the Windows files, etc are on it and the drive seems to work fine, but I cannot boot from it. How can I make it bootable without a new install of Windows?