Try uninstalling the following items in order:
Apple mobile device (might not be installed)
Apple software update
iTunes
Quicktime
Now restart computer.
Now download itunes743setup and save it to your desktop.
Disable any anti-virus and internet security.
Now install itunes.
If this does not work, then there is something blocking the apple mobile device from installing.
this article from the apple support website will help turn everything off except what the computer needs.
http://docs.info.apple.com/article.html?artnum=302538
Uninstall the items previously mentioned.
Restart the computer again.
Then install itunes again.
The apple mobile device driver is installed with itunes.
Hope this helps.