If you had performed a Wubi installation of Ubuntu 12.04.1 64-bit, Wubi would have rebooted and automatically started the real Linux installation.
Sadly, for some unknown reason, Mint4win will not do the same when installing Mint 13 x64. I.e. having finshed the preparatory work under Windows, Mint4win will reboot the machine. The Linux Mint live system will come up. But the real Linux Mint installation will not be launched automatically.
Therefore, you will have to do so yourself.
This means, when the live system has started up,
- on the Live System Desktop click on the icon labelled "Install Linux Mint" in order to proceed with the installation.
- Follow the instructions on the screen.
- In particular make sure that you select /dev/loopX as the target for the root.disk (ext4 file system of your Mint installation) and the same /dev/loopX as the target for Grub. The "X" inside /dev/loopX will be 1 or 2 actually. It should be obvious when looking at the offered choices.
Never ever allow Grub to go to /dev/sda on Mint4win installations!
- Unless you have committed a mistake, the second phase of the Mint 13 installation should finish without any problems.
Next time you boot and select to run "Linux Mint", you should be running the fully installed system and you should be able to login as the user which you have created during the second part of the installation (see above)