Comment 8 for bug 364166

Documented at <https://wiki.ubuntu.com/JauntyJackalope/ReleaseNotes#Wubi reuses a pre-existing "ubuntu" directory and removes it on uninstallation>:

 If there is a pre-existing directory called "ubuntu" in the target drive, it will be reused during the Windows installation and the full directory will be removed when uninstalling (364166). This will result in the loss of any files which were originally in that directory. It is recommended to rename any directory called "ubuntu" before proceeding with a Wubi installation.