.First install the driver to your pc which is necessary.Without installing the necessary driver processing further proceeding is only waste of time.If you do not install driver correctly then you do not install the rom correctly.
2.Second,Check that any another usb driver related to your mobile is not installed on your PC using USB DEVIEW(Download it from link below).If you have any type of driver installed related to Mt65xx the uninstall it or related to any type of android driver uninstall it.I am providing the link of youtube see there how to install the