I am logged in as administrator don't know why I get this error message this is the worst....

Hello sharethaj,

unfortunately you don't say which OS and Melodyne editon and version this is, but please be aware that e.g. Windows 7 requires you to
1) log in as an administrator,
2) right-click the Melodyne installer and choose Run as administrator, and possibly
3) do the same with the DAW that is going to host Melodyne as a plug-in

Does this work? If it doesn't, please give us more details on your system and what you have tried so far.