Did you leave the other hard drive in your system during the install, and is it still there?
The BCD store holds the info about boot information, which is not on the MBR. If you only have the one drive, a Startup Repair run from the Recovery Environment should repair the install, after running a few times. But a command such as Bootrec /rebuildbcd would be more appropriate for your situation. If you did anything to change the original drive configuration, you should let us know.
Anytime you install or repair an OS, it is always best to remove any unnecessary drives to keep the system from using the wrong drive.