To me it sounds like sysprep didn’t seal your image properly.
You should set up a fresh Windows 7 x64 installation, go into audit mode via CTRL+Shift+F3, install all current updates, customize as needed, stop the wmpnetworksvc service and then let sysprep seal the image with the generalize option checked.
Attached you’ll find my unattend.xml which I use to deploy Windows 7 Pro x64. It is working just fine.
Instead of the build in HII function I use a custom solution where I copy the necessary drivers to “C:\Drivers” after the unattend.xml injection and let dpinst do the installation in the specialize phase of Windows setup. EMiranda explained it here: http://community.landesk.com/support/thread/9307
unattend.xml 4.9 K