What does uninstall-wubi.exe do? Does it uninstall just wubi or complete Ubuntu? I installed Ubuntu 12.04 in Windows 7 and now have Windows 8 in place of Windows 7 and I want a fresh copy of Ubuntu 12.04
It removes the Ubuntu (or other flavour) that you installed using
In other words it reverses what running
Since Wubi doesn't interfere with how Windows boots, it cannot stop it booting either. So you can safely install and uninstall without affecting Windows.
Finally, in your situation, you installed Windows 8 over Windows 7. This means that the boot entry and the registry entries are all gone. All you have left is the