New
#11
It wasn't a BIOS function.
In older versions of Windows, F8 allowed you to choose to boot in safe mode. I don't recall the last Windows version that supported it, but it was gone in 8. Microsoft didn't bring it back in 10.
I believe that one of the ways of getting into safe mode is to do an abnormal shutdown (hold the power button down until the machine shuts down). You may have to do that several times until it gives you the option. (Haven't done that yet myself in 10.)