Cherche-du-paix, welcome to the forum.
When requesting help you should always include the make/model of the computer and/or monitor. This information is necessary for us to review the specifications of them.
I have run Linux Ubuntu and Windows as a dual boot for years. I normally use a separate hard drive for Linux. This way there is no conflict with Windows. Also, it gives you a backup if one of the drives fails.
Here is a link to the Linux Mint Forums. These folks are the ones who know how to work with it. I suggest asking for help there.
Please click "KUDOS star" if I have helped you and click "Accept as Solution" if your problem is solved.