I am not sure but yes I think you can keep it like this.

I think Wubi is a fantastic idea espcially for people testing the waters as
it is so easy to do but if I understand Wubi correctly it installs itself
like an application under Windows. So you have a very stable secure system
running off an insecure weak operating system.
My gut instinct is that that is a bad idea.

I think once you become more used to Linux you should install Ubuntu in its
own right on its own partition and not as a windows application.