Can anyone tell me what is "metro bootloader" and how to use it?

[KRGiff]

I could not find anything in the documentations.

Thanks.

 

[Terry60]

"metro" is what they used to call the W8 desktop (with all the app squares) till MS was stopped from using the term for proprietary reasons.
Metro bootloader is shorthand (non MS) for the blue GUI boot menu, as opposed to the black legacy menu (no mouse) which existed up until W7.