I am trying to uninstall Ubuntu because a while ago (Before the new version came out.) I could not install Ubuntu, now I would like to install the new one but first I would like to get rid of the dual boot option that comes up before getting into an operating system by uninstalling it. When I try to get into this happens (In the pictures, is the error.) :
I would suggest using this guide and using GRUB instead of Window's ntldr as your bootloader.
In other words: just do a normal Ubuntu intall (not from wubi) and let it handle the bootloader (but first I would suggest trying to "uninstall" ubuntu from wubi such that ntldr's boot.ini is restored to it's proper state)