It drives me crazy when applications install themselves into the system tray without giving me a choice during setup. QuickTime has no good reason to be in the system tray, but it’s there anyway after you install iTunes.
To remove it, all you have to do is right-click on the icon in the system tray, and choose “Quicktime Preferences” from the menu.
Click on the Advanced tab.
Near the bottom, uncheck the checkbox for “Install QuickTime icon in system tray”
If you are using Windows Vista, you will get this message when you close the dialog window.
Just click the “This control panel works correctly” button, and the icon should be gone forever.