Whats the exact problem? GRUB does not show up and Windows boots directly? You could try the rescue mode of the installer to reinstall GRUB, reFind is normally not needed on a PC system to dual boot with Windows.
Once you get GRUB up and running, you should consider installing the package os-prober. update-grub will then add the Windows system to the GRUB menu. Even in Windows 10 days, updates can overwrite GRUB from time to time, so you should keep a copy of the Debian installer media for fixing this when needed.
