Today I was downloading a Mac OSX skin for login and it required me to change the authui.dll in System 32 to authui_original.dll and replace it with the downloaded one. I cannot copy the downloaded one to the folder or change it back to authui.dll because whenever I try it says I need administrative permission to edit or copy the file, however if I try to do so it says: "Can't access control editor. A device attached to the system is not working", and I speculate this is because of another program that became unresponsive while I hit the button to give it Administrative properties. I can't close it because the authui.dll affects the Task Manager and the login so I am extremely scared to restart. PLEASE HELP!