This is not really an issue since what you are doing is basically a re-install on the same computer but computer management on the One Care account page would be a nice feature.
I have the same issue. Previous disk died on me (i.e. no way to uninstall). Why can't they just give us a simple interface to mange the computers (See how Itunes does it for example). All this re-install, clean-up etc is a mess.
This is not really an issue since what you are doing is basically a re-install on the same computer but computer management on the One Care account page would be a nice feature.