Had to pull the power and restart, as nothing else worked, couldn't even coax a right click force quit from the menu bar. I cannot see how to reinstall my current itunes, as this short window box message is asking me to do. I attempted to go ahead and install a new iTunes 8.4.2 for G3 but it said I'm already running a newer version of iTunes. 2005 Mac mini running 10.4.2. I have no other apps of great disk space running. Everything I click on that says iTunes, like in system profile etc, just brings up the same message box: "corrupt or improperly installed". I've tried restarting the mini. Nothing else is effected. Thanks in advance.