I have the same problem, none of this sorted it unfortunately.
Turned off Panda Global Protection 2010, uninstalled itunes64, reinstalled it, no option to unblock so figure it already is? All that went fine, but when I run it, no luck, still get the error. If i try compatability mode i get an -itunes would rather run as Windows 7- message, click ok to let it run and i get the error message again.
Tried running it as administrator but no difference.
Also tried the latest 32bit version, only to get a -run 64-bit version- message.
It's enough to make a grown man cry
Any help or ideas would be very much appreciated!