I would try uninstalling Quicktime first. "default.ico" appears to just be the icon & or skin.
Anyway I would remove from Add/Remove Programs & then do a Search from the startmenu for Quicktime & delete all finds & then run a Registry Cleaner & delete all relavent finds. Then reboot & try the install again.
Here is a free basic Registry Cleaner:
http://www.hoverdesk.net/freeware.htm
A further check would be to run the Windows Installer CleanUp Utility
http://support.microsoft.com/default...b;en-us;290301
& clear any Quicktime entries.
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