Open Synaptic Package Manager and remove Nautilus. It's in the Administration section of the menu on Mint 13.
If you want to keep your windows install how it sits, and you really want to try Mint, you could try installing Mint in a virtual environment like Virtualbox
. Then you can install it exactly as you would with a normal install, you don't lose or change anything, and you can make backups to test things out. You can play with it and learn to your heart's content, and when you break something your unbroken system is just a few clicks away.