The ALERT message in your original post indicated the bootloader is looking for a partition identified by a UUID "super long number" which doesn't exist. You can run the blkid command from a terminal and compare the output to see if that UUID from the Alert message shows any where.
If you installed the bootloader for to the mbr of sdc and Elementary is on a partition on sdc, it should boot if sdc is set to first boot priority in the BIOS.
Probably the best thing to do is to go to the bootinfoscript site below, download and run it from any Linux Live medium and post the output, a results.txt file, here.
There is a link in the Description box on that page with instructions.