Recently Quicktime has started playing up. I cannot find the program file but cannot install a new version either as it says the disk is dimmed by a newer version. what do i do to get it working again.
repair permissions of your main disk in Disk Utility found in the application folders.
then search in a finder window for quicktime, or qt. delete the application if it appears, then also delete any com.apple.quicktime.plist or similar files. empty trash, try installing again.