iTunes requires QuickTime 7.5.5 or later.

QuickTime 7.5.5 for Leopard - http://support.apple.com/kb/DL27

QuickTime 7.7 for Leopard - http://support.apple.com/kb/dl761

= New version of Quicktime installed but application reports it needs to have that version installed =

Open Application > Utilities > System Profiler and check the Quicktime version in Frameworks vs. the version in Applications. I recently helped where the person had re-installed their operating system. It had kept the newer Player application but had reverted to an earlier version of the underlying support framework that works with many applications. Re-installing Quicktime 7.7 took care of the problem. Do this manually, not with Software Update.

Installation get stuck at "configuring installation" - https://discussions.apple.com/thread/2592979?threadID=2592979 - uninstall Quicktime before installing.

Here's my (it took me less than 10 minutes) VERY QUICK FIX (after I did an "Archive and Reinstall" of Mac OS 10.5 because a bad PCI-X card suddenly and unexpectedly crashed, and then totally corrupted my System files):

1.) DELETE whatever version you have of QuickTime from your computer (and just to be SAFE, be certain you have the Registration Code written down before you Delete Quicktime, IF you own a license to QuickTime Pro);

2.) DOWNLOAD and INSTALL the latest version of iTunes, e.g., v10.6.1 <http://www.apple.com/itunes/download/> (do NOT open iTunes after downloading and installing);

3.) DOWNLOAD and INSTALL QuickTime version 7.7 <http://support.apple.com/kb/dl761> (after downloading and installing, OPEN QuickTime and re-enter your QuickTime Pro Registration Code, IF you have one);

4.) IF necessary, Move/Replace your new and most likely empty iTunes folder with your old and most likely chock full iTunes folder... my old iTunes folder was located here: (Macintosh HD>Previous Systems>Users>"my user name">Music>iTunes); and,

5.) OPEN iTunes Application -- and enjoy your media!

GOOD LUCK!

P.S. -- FYI: I'm running Mac OS 10.5.8 on a PowerMac G5 with Dual 2 GHz Processor and 4 GB DDR SDRAM... and my iTunes app v10.6.1, including ALL of my media, and my QuickTime Pro v7.7 -- are all working/running perfectly fine now after I followed the five (5) EZ Steps listed above!

16-May-2012