Bios is not a boot commander and this is not INT13 MBR its UEFI GPT. This is one of the many reasons why CLONING is not supported by Dell or Microsoft. microsoft policy for disk duplication of windows installations [URL]    
Hi I have installed a 500GB SSD in my Inspiron planning to use this as the boot drive and keep the standard 1TB HDD as storage. I have cloned the HDD to the SSD and successfully booted from it. I have not re-formatted the HDD and would prefer to avoid doing that.  In bios setup I can uncheck the (Toshiba) hard drive in the boot sequence and the machine will boot from the SSD and let me access the HDD. However, it does not remember this setting so the next time I restart it reverts to booting from the HDD. I think I have saved the setting. I have also tried saving it as a 'custom set up' So far neither seems to keep this configuration between restarts. Am I missing something simple here? Help would be most welcome. And, while trying to research this, I couldn't find any detailed description of the Bios settings (there's a bit in the manual but it's sketchy). Anyone know if a more detailed treatment is available anywhere?   Thanks
Inspiron 3670 - making boot order changes in bios permanent