Ok, I'm getting the parts together to build a new Linux box. One of those parts is my secondary HDD, where my Linux partition lives. I used GRUB as the bootloader in the MBR and everything worked ...

I don't normally have to deal with GRUB in my regular Linux usage apart from the boot menu. Since everything's set up correctly on installation, I can just let it be.

Bootloader gap: Many Linux distributions are at risk There is a security gap in the bootloader shim, which also allows secure booting for non-Windows operating systems.

If you are unable to boot into Windows after installing Linux Mint or any other distro on your computer, try updating GRUB, using Boot Repair, and adjusting UEFI settings.