You can open an Administrative command prompt and type the command below to place boot files in the C partition. Make sure and put spaces where indicated or copy and paste the commands.
bcdboot c:\windows /s c:
Then shut your system down and disconnect the other drive. During reboot, make sure drive 0 is set as the primary boot device. The system should now boot normally but you may not have recovery options available. So before you shut the system down you might run the command below in case you need the info, it should show the path to the recovery tools so save the listing.
Thanks, this fixed my issues that i wasted too much time resolving. It is crazy that MS decides which drive to put the boot files on. The boot files should go on the drive with the OS for anyone without a dual boot.