A directory *has* to be owned by you, that is, your username. So not root. If you can mount your NTFS partition as your currently logged in username, it may work (not sure since a Wineprefix consists of a lot of symlinks, which NTFS would have to support). Note that it is highly discouraged you do this; Wine was written for "normal" Linux filesystems. Why are you trying to do this exactly?
