Hi,
Are you installing our ISO?
Make sure that from the BIOS settings, check if you have BIOS CSM mode enabled. It is recommended on the NC02U to have this enabled as this forces the Debian installer to boot into PC compatibility mode (and not EFI) and also install GRUB on the MBR rather than the EFI layout.
When you boot into the Debian installer, go through the steps until you've reached the question about installing grub.
Pause and do not proceed with grub install just yet.
Hold ctrl+alt + F2. You will be presented with a terminal in which you will type: tail -f /var/log/syslog. Like this you can monitor what happens when you install grub. You will switch between the terminal and the installer screen this way. CTRL+ALT+F1 will take you back to the installer.
Go back to the installer (ctrl+alt+F1). Install grub and make sure its selected to install on the MBR of the boot disk usually /dev/sda1. If it fails, CTRL+ALT+F2 takes you back to the syslog output and you can get the exact reason why grub is failing. If it fails reply back with the error message that GRUB logs to syslog. Check first though that you have CSM enabled to disable Debian going into EFI mode from the BIOS.
Let me know of your results.