You have already installed Mint successfully? The Live DVD does not have Grub, but a different bootloader, that's why I am asking this.
Any options set in Grub, are used for only one boot. If you have managed to boot your system with some option, then that option can be saved in the /etc/default/grub file (you need to run sudo update-grub in terminal after editing /etc/default/grub).
If nomodeset does not fix your problems, I think it's not related to the NVIDIA GPU. In todays laptops with NVIDIA Optimus, Intel HD Graphics is used by default and the NVIDIA GPU is only used for accelerating programs that don't run well enough on Intel. So this should not cause much problems when booting.
Have you already tried launching Recovery Mode, and then choosing to continue normal boot on the recovery menu? That way, errors which occur during boot are actually shown.
Registered Linux User #528502
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