Thank you for the feedback provided regarding your experience with Windows 7* and the NUC6i3SYH.
I would like you to read the following article explaining MBR / GPT, I found it very informative.
Additionally, here you can find some additional information about Secure Boot.
If you installed the OS with GPT, you would be able to use secure boot.
In case you require any further information or support, feel free to contact us back.
I understand and I am glad it is working properly.
Now, regarding the FAQ provided, it was to give you a better overview of what Secure Boot is and what does it do.
As long as you have GPT, you would be able to use Secure Boot.
If you encounter with any additional questions or inquiries, do not hesitate to contact the Intel Communities again.