Thanks Matt and others for the responses. I tried the approach that was recommend by Matt. The program uninstalled successfully and subsequently reinstalled successfully during which time my antivirus software was temporarily disabled. However, when attempting to run MC 16, the popup window came up again and stated that the license was expired. I then tried a "restore" and got the same error message as before (i.e. "Error restoring Media Center License: Unknown Error"). A couple of things to note. First, this computer has never had a previous version of MC. Second, some time after MC 16 was initially installed in on June 6th, the computer name was change from something like "owners-pc" to "Music-Server". Could that possibly be causing the problem and if so, is there someway I can get a new installation or whatever you think is necessary to get this working.