How to make an entrance to different OSes from the BIOS?

Question

Loaders

I don’t know how to formulate the question correctly, but I want to make it so that when you turn on the computer, instead of loading Windows / Linux / Votever, a choice first appears, and only after the choice a certain OS starts loading
. I did this on the computer where I passed an internship and there were 4 different OSes installed
So far I have Windows installed, I don’t want to demolish it, but I just want to add Linux as a second choice

Answer 1

Бутлоадер линукса (обычно это grub) при установке автоматически найдёт винду и добавит её в меню выбора ОС. Скорее всего.