HDCLone results in "Operating System Not Found"

I used HDClone to copy my Win7 image from an internal 100GB drive to a second internal 250GB drive. Everything seemed to work fine, but now both drives are giving me an "Operating System Not found error." I've tried each drive alone in each bay. I even tried putting them both back in so they are in their original locations. Same error every time. Any advice is greatly appreciated.