It is strange that you the install did not complete but you got no error messages.
I have to go now until tomorrow, but I think it is worth trying the install again.
First uninstall the components of iTunes using this method:
http://support.apple.com/kb/HT1923
There is a version in French if you need it.
Download iTunes again from:
http://www.apple.com/itunes/download/
Save it in your downloads folder. You should get iTunes64setup.exe
Then try installing, You should be asked it it is OK to run the installer. Can you see the installer working and does it complete without any error messages?