iTunes.exe has been set to run in compatibility mode for an older version of windows, for best results, turn off compatibility mode for itunes before you open it
i've been able to replicate that one on belladonna, although the technique for getting rid of it may not work for everyone.
if you have itunes version 6.0.2.23 or higher running in Win 95 or Win 98 compatibility mode, it will give you a version of that message, and itunes won't launch at all.
with iTunes 7.0.0.70, if you have Win XP and you're running in Win 2000 compatibility mode, you'll get that message but itunes
will launch.
so the best thing to try first is to use the instructions from the following document to switch off compatibility mode
altogether:
iTunes for Windows: Audio files do not play in iTunes 5 or 6