I'm on a fresh install of Elementary OS Loki. Right after the install screen about installing third-party and background updates, I have this pop-up:
Force UEFI installation?
This machines's firmware has started the installer in UEFI mode but it looks like there may be existing operating systems already installed using "BIOS compatibility mode". If you continue to install Debian in UEFI mode, it might be difficult to reboot the machine into any BIOS-mode operating systems later.
If you wish to install in UEFI mode and don't care about keeping the ability to boot one of the existing systems, you have the option to force that here. If you wish to keep the option to boot an existing operating system, you should choose NOT to force UEFI installation here.
In my case, the installed drives are blank, so I don't know why this message is being thrown, but is it smart to default new installs into UEFI mode? (Thus the only reason for desiring the old BIOS method would be compatibility with older, UEFI-incompatible operating systems?) Does this affect future installs of modern operating systems on this computer? Just wanted to confirm as I imagine many others will have the same questions.