URGENT BOOT-UP PROBLEM! HELP ME

I installed on my puter a second hard drive to copy its info into mine in order to reformat it and reinstall windows in it. I did all that with it installed on my computer and now my computer won't boot-up with my regular hard drive, it keeps reading the other one as the start-up. When I change the boot sequence at start-up it still does not recognize the old one.

Any help will be appreciated, thanks!