Do you have a windows operating system on both drives?
Is one of the windows just a data partition?
What, if anything, are you now able to boot?
If you are not able to boot Debian from the second drive after the installation, you probably didn't install Debian Grub to the master boot record. Which hard drive is set to first boot priority? The Fedora drive or the Debian drive? If you installed Debian Grub to the master boot record of its (second) drive, you need to set the second drive to first boot priority in the BIOS. If you want to boot from Fedora Grub, you need to put an entry for Debian in the Fedora Grub file, menu.lst or grub.conf.
If you provide answers to the questions above and state what your intentions are you should get some help.