If you are going to install Mint, might as well do it the REAL way; not some crappy way where you'll suffer the headaches of fragmentation and system impact due to using the NTFS (or FAT) filesystem. Mint4Win doesn't install Linux in its native format(s) (which are ext2/3/4, although it also supports JFS and RFS and a few others).
It's easy to install it the TRUE way:
1. Download the Mint iso
2. Get a 2GB flashdrive (make sure it's empty)
3. Download UNetbootin from www.unetbootin.sourceforge.net
4. Plug in 2GB flashdrive
5. Start the UNetbootin app
6. Point the diskimage to the Mint iso
7. Select the USB drive
8. Click ok and let the app do its thing. It will ask you to restart your computer once finished. Comply.
9. Access your boot menu (when your computer boots up, look for something that says "Press <X> to access boot menu" and press that key (could be ESC, F12, or F10)
10. Select flashdrive and boot off of it. Install Mint... (If you need help doing this part, post a screenshot of the partitions or harddrives in GParted).