iPhone not supported under 64-bit Windows XP or Vista -- oops
 

*Source: enGadget (http://www.engadget.com/2007/06/30/i...-vista-oops/)*
________
Struggling with your new iPhone on a 64-bit Windows Vista or XP system? Take solace, you're not alone. The error message, "The software required for iPhone is not installed. Run the iTunes installer to remove iTunes, then install iTunes again." is Apple's magical way of telling you that iTunes is not supported on 64-bit flavors of Microsoft's operating systems.

More...