Something You Ought to Know About iPhones

Apple buried iPhones incompatability to Windows XP and Vista 64-bit version in their support document.

Article 301301 says this:

iTunes for Windows not currently supported on any 64-bit editions of Windows

iTunes is currently not supported in Windows XP Professional x64 Edition or any 64-bit edition of Windows Vista. Features may or may not work correctly. One example is reading or writing to an optical drive (CD-ROM, CD-RW, DVD-ROM, DVD-RW). It’s also possible iTunes for Windows may not successfully install.

This document will be updated when more information is available.